diff --git a/securedrop/create-dev-data.py b/securedrop/create-dev-data.py
index 07e6e870e4..3f6ef3845f 100755
--- a/securedrop/create-dev-data.py
+++ b/securedrop/create-dev-data.py
@@ -15,7 +15,7 @@
 
 from sdconfig import config
 from db import db
-from models import Journalist, Reply, Source, Submission
+from models import Journalist, Reply, SeenReply, Source, Submission
 from specialstrings import strings
 
 
@@ -138,6 +138,9 @@ def create_source_and_submissions(
             journalist = journalist_who_replied
         reply = Reply(journalist, source, fname)
         db.session.add(reply)
+        db.session.flush()
+        seen_reply = SeenReply(reply_id=reply.id, journalist_id=journalist.id)
+        db.session.add(seen_reply)
 
     db.session.commit()
 
diff --git a/securedrop/journalist_app/api.py b/securedrop/journalist_app/api.py
index aac8e7cfd7..e6d487e978 100644
--- a/securedrop/journalist_app/api.py
+++ b/securedrop/journalist_app/api.py
@@ -1,7 +1,8 @@
+import collections.abc
 import json
 
 from datetime import datetime, timedelta
-from typing import Tuple, Callable, Any
+from typing import Tuple, Callable, Any, Set, Union
 
 import flask
 import werkzeug
@@ -15,7 +16,7 @@
 
 from db import db
 from journalist_app import utils
-from models import (Journalist, Reply, Source, Submission,
+from models import (Journalist, Reply, SeenReply, Source, Submission,
                     LoginThrottledException, InvalidUsernameException,
                     BadTokenException, WrongPasswordException)
 from sdconfig import SDConfig
@@ -69,6 +70,7 @@ def get_endpoints() -> Tuple[flask.Response, int]:
                      'all_users_url': '/api/v1/users',
                      'submissions_url': '/api/v1/submissions',
                      'replies_url': '/api/v1/replies',
+                     'seen_url': '/api/v1/seen',
                      'auth_token_url': '/api/v1/token'}
         return jsonify(endpoints), 200
 
@@ -268,6 +270,9 @@ def all_source_replies(source_uuid: str) -> Tuple[flask.Response, int]:
 
             try:
                 db.session.add(reply)
+                db.session.flush()
+                seen_reply = SeenReply(reply_id=reply.id, journalist_id=user.id)
+                db.session.add(seen_reply)
                 db.session.add(source)
                 db.session.commit()
             except IntegrityError as e:
@@ -311,6 +316,49 @@ def get_all_replies() -> Tuple[flask.Response, int]:
         return jsonify(
             {'replies': [reply.to_json() for reply in replies if reply.source]}), 200
 
+    @api.route("/seen", methods=["POST"])
+    @token_required
+    def seen() -> Tuple[flask.Response, int]:
+        """
+        Lists or marks the source conversation items that the journalist has seen.
+        """
+        user = _authenticate_user_from_auth_header(request)
+
+        if request.method == "POST":
+            if request.json is None or not isinstance(request.json, collections.abc.Mapping):
+                abort(400, "Please send requests in valid JSON.")
+
+            if not any(map(request.json.get, ["files", "messages", "replies"])):
+                abort(400, "Please specify the resources to mark seen.")
+
+            # gather everything to be marked seen. if any don't exist,
+            # reject the request.
+            targets = set()  # type: Set[Union[Submission, Reply]]
+            for file_uuid in request.json.get("files", []):
+                f = Submission.query.filter(Submission.uuid == file_uuid).one_or_none()
+                if f is None or not f.is_file:
+                    abort(404, "file not found: {}".format(file_uuid))
+                targets.add(f)
+
+            for message_uuid in request.json.get("messages", []):
+                m = Submission.query.filter(Submission.uuid == message_uuid).one_or_none()
+                if m is None or not m.is_message:
+                    abort(404, "message not found: {}".format(message_uuid))
+                targets.add(m)
+
+            for reply_uuid in request.json.get("replies", []):
+                r = Reply.query.filter(Reply.uuid == reply_uuid).one_or_none()
+                if r is None:
+                    abort(404, "reply not found: {}".format(reply_uuid))
+                targets.add(r)
+
+            # now mark everything seen.
+            utils.mark_seen(list(targets), user)
+
+            return jsonify({"message": "resources marked seen"}), 200
+
+        abort(405)
+
     @api.route('/user', methods=['GET'])
     @token_required
     def get_current_user() -> Tuple[flask.Response, int]:
diff --git a/securedrop/journalist_app/col.py b/securedrop/journalist_app/col.py
index 0c45619a1d..a348bb3854 100644
--- a/securedrop/journalist_app/col.py
+++ b/securedrop/journalist_app/col.py
@@ -13,16 +13,15 @@
     url_for,
 )
 from flask_babel import gettext
-from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm.exc import NoResultFound
 
 from db import db
-from models import Reply, SeenFile, SeenMessage, SeenReply, Submission
+from models import Reply, Submission
 from journalist_app.forms import ReplyForm
 from journalist_app.utils import (make_star_true, make_star_false, get_source,
                                   delete_collection, col_download_unread,
                                   col_download_all, col_star, col_un_star,
-                                  col_delete)
+                                  col_delete, mark_seen)
 
 
 def make_blueprint(config):
@@ -94,25 +93,18 @@ def download_single_file(filesystem_id, fn):
 
         # mark as seen by the current user
         try:
-            journalist_id = g.get("user").id
+            journalist = g.get("user")
             if fn.endswith("reply.gpg"):
                 reply = Reply.query.filter(Reply.filename == fn).one()
-                seen_reply = SeenReply(reply_id=reply.id, journalist_id=journalist_id)
-                db.session.add(seen_reply)
+                mark_seen([reply], journalist)
             elif fn.endswith("-doc.gz.gpg") or fn.endswith("doc.zip.gpg"):
                 file = Submission.query.filter(Submission.filename == fn).one()
-                seen_file = SeenFile(file_id=file.id, journalist_id=journalist_id)
-                db.session.add(seen_file)
+                mark_seen([file], journalist)
             else:
                 message = Submission.query.filter(Submission.filename == fn).one()
-                seen_message = SeenMessage(message_id=message.id, journalist_id=journalist_id)
-                db.session.add(seen_message)
-
-            db.session.commit()
+                mark_seen([message], journalist)
         except NoResultFound as e:
             current_app.logger.error("Could not mark {} as seen: {}".format(fn, e))
-        except IntegrityError:
-            pass  # expected not to store that a file was seen by the same user multiple times
 
         return send_file(current_app.storage.path(filesystem_id, fn),
                          mimetype="application/pgp-encrypted")
diff --git a/securedrop/journalist_app/utils.py b/securedrop/journalist_app/utils.py
index 47d01a33a9..32af2e512b 100644
--- a/securedrop/journalist_app/utils.py
+++ b/securedrop/journalist_app/utils.py
@@ -9,6 +9,7 @@
 from flask import (g, flash, current_app, abort, send_file, redirect, url_for,
                    render_template, Markup, sessions, request)
 from flask_babel import gettext, ngettext
+from sqlalchemy.exc import IntegrityError
 
 import i18n
 
@@ -163,6 +164,32 @@ def validate_hotp_secret(user: Journalist, otp_secret: str) -> bool:
     return True
 
 
+def mark_seen(targets: List[Union[Submission, Reply]], user: Journalist) -> None:
+    """
+    Marks a list of submissions or replies seen by the given journalist.
+    """
+    for t in targets:
+        try:
+            if isinstance(t, Submission):
+                t.downloaded = True
+                if t.is_file:
+                    sf = SeenFile(file_id=t.id, journalist_id=user.id)
+                    db.session.add(sf)
+                elif t.is_message:
+                    sm = SeenMessage(message_id=t.id, journalist_id=user.id)
+                    db.session.add(sm)
+                db.session.commit()
+            elif isinstance(t, Reply):
+                sr = SeenReply(reply_id=t.id, journalist_id=user.id)
+                db.session.add(sr)
+                db.session.commit()
+        except IntegrityError as e:
+            db.session.rollback()
+            if 'UNIQUE constraint failed' in str(e):
+                continue
+            raise
+
+
 def download(zip_basename: str, submissions: List[Union[Submission, Reply]]) -> werkzeug.Response:
     """Send client contents of ZIP-file *zip_basename*-<timestamp>.zip
     containing *submissions*. The ZIP-file, being a
@@ -179,31 +206,7 @@ def download(zip_basename: str, submissions: List[Union[Submission, Reply]]) ->
         zip_basename, datetime.datetime.utcnow().strftime("%Y-%m-%d--%H-%M-%S")
     )
 
-    # mark as seen by the current user
-    journalist_id = g.get("user").id
-    for item in submissions:
-        if item.filename.endswith("reply.gpg"):
-            already_seen = SeenReply.query.filter_by(
-                reply_id=item.id, journalist_id=journalist_id
-            ).one_or_none()
-            if not already_seen:
-                seen_reply = SeenReply(reply_id=item.id, journalist_id=journalist_id)
-                db.session.add(seen_reply)
-        elif item.filename.endswith("-doc.gz.gpg"):
-            already_seen = SeenFile.query.filter_by(
-                file_id=item.id, journalist_id=journalist_id
-            ).one_or_none()
-            if not already_seen:
-                seen_file = SeenFile(file_id=item.id, journalist_id=journalist_id)
-                db.session.add(seen_file)
-        else:
-            already_seen = SeenMessage.query.filter_by(
-                message_id=item.id, journalist_id=journalist_id
-            ).one_or_none()
-            if not already_seen:
-                seen_message = SeenMessage(message_id=item.id, journalist_id=journalist_id)
-                db.session.add(seen_message)
-        db.session.commit()
+    mark_seen(submissions, g.user)
 
     return send_file(
         zf.name,
diff --git a/securedrop/models.py b/securedrop/models.py
index 2967a1db20..a88d907970 100644
--- a/securedrop/models.py
+++ b/securedrop/models.py
@@ -100,11 +100,10 @@ def journalist_filename(self) -> str:
     def documents_messages_count(self) -> 'Dict[str, int]':
         self.docs_msgs_count = {'messages': 0, 'documents': 0}
         for submission in self.submissions:
-            if submission.filename.endswith('msg.gpg'):
-                self.docs_msgs_count['messages'] += 1
-            elif (submission.filename.endswith('doc.gz.gpg') or
-                  submission.filename.endswith('doc.zip.gpg')):
-                self.docs_msgs_count['documents'] += 1
+            if submission.is_message:
+                self.docs_msgs_count["messages"] += 1
+            elif submission.is_file:
+                self.docs_msgs_count["documents"] += 1
         return self.docs_msgs_count
 
     @property
@@ -212,7 +211,23 @@ def __init__(self, source: Source, filename: str) -> None:
     def __repr__(self) -> str:
         return '<Submission %r>' % (self.filename)
 
-    def to_json(self) -> 'Dict[str, Union[str, int, bool]]':
+    @property
+    def is_file(self) -> bool:
+        return self.filename.endswith("doc.gz.gpg") or self.filename.endswith("doc.zip.gpg")
+
+    @property
+    def is_message(self) -> bool:
+        return self.filename.endswith("msg.gpg")
+
+    def to_json(self) -> "Dict[str, Union[str, int, bool]]":
+        seen_by = {
+            f.journalist.uuid for f in SeenFile.query.filter(SeenFile.file_id == self.id)
+            if f.journalist
+        }
+        seen_by.update({
+            m.journalist.uuid for m in SeenMessage.query.filter(SeenMessage.message_id == self.id)
+            if m.journalist
+        })
         json_submission = {
             'source_url': url_for('api.single_source',
                                   source_uuid=self.source.uuid) if self.source else None,
@@ -221,11 +236,14 @@ def to_json(self) -> 'Dict[str, Union[str, int, bool]]':
                                       submission_uuid=self.uuid) if self.source else None,
             'filename': self.filename,
             'size': self.size,
-            'is_read': self.downloaded,
+            "is_file": self.is_file,
+            "is_message": self.is_message,
+            "is_read": self.seen,
             'uuid': self.uuid,
             'download_url': url_for('api.download_submission',
                                     source_uuid=self.source.uuid,
                                     submission_uuid=self.uuid) if self.source else None,
+            'seen_by': list(seen_by)
         }
         return json_submission
 
@@ -284,17 +302,21 @@ def __init__(self,
     def __repr__(self) -> str:
         return '<Reply %r>' % (self.filename)
 
-    def to_json(self) -> 'Dict[str, Union[str, int, bool]]':
-        username = "deleted"
-        first_name = ""
-        last_name = ""
-        uuid = "deleted"
+    def to_json(self) -> "Dict[str, Union[str, int, bool]]":
+        journalist_username = "deleted"
+        journalist_first_name = ""
+        journalist_last_name = ""
+        journalist_uuid = "deleted"
         if self.journalist:
-            username = self.journalist.username
-            first_name = self.journalist.first_name
-            last_name = self.journalist.last_name
-            uuid = self.journalist.uuid
-        json_submission = {
+            journalist_username = self.journalist.username
+            journalist_first_name = self.journalist.first_name
+            journalist_last_name = self.journalist.last_name
+            journalist_uuid = self.journalist.uuid
+        seen_by = [
+            r.journalist.uuid for r in SeenReply.query.filter(SeenReply.reply_id == self.id)
+            if r.journalist
+        ]
+        json_reply = {
             'source_url': url_for('api.single_source',
                                   source_uuid=self.source.uuid) if self.source else None,
             'reply_url': url_for('api.single_reply',
@@ -302,14 +324,15 @@ def to_json(self) -> 'Dict[str, Union[str, int, bool]]':
                                  reply_uuid=self.uuid) if self.source else None,
             'filename': self.filename,
             'size': self.size,
-            'journalist_username': username,
-            'journalist_first_name': first_name,
-            'journalist_last_name': last_name,
-            'journalist_uuid': uuid,
+            'journalist_username': journalist_username,
+            'journalist_first_name': journalist_first_name,
+            'journalist_last_name': journalist_last_name,
+            'journalist_uuid': journalist_uuid,
             'uuid': self.uuid,
             'is_deleted_by_source': self.deleted_by_source,
+            'seen_by': seen_by
         }
-        return json_submission
+        return json_reply
 
 
 class SourceStar(db.Model):
diff --git a/securedrop/tests/conftest.py b/securedrop/tests/conftest.py
index 043b77bef2..625589e86a 100644
--- a/securedrop/tests/conftest.py
+++ b/securedrop/tests/conftest.py
@@ -208,7 +208,7 @@ def test_submissions(journalist_app):
 def test_files(journalist_app, test_journo):
     with journalist_app.app_context():
         source, codename = utils.db_helper.init_source()
-        utils.db_helper.submit(source, 2)
+        utils.db_helper.submit(source, 2, submission_type="file")
         utils.db_helper.reply(test_journo['journalist'], source, 1)
         return {'source': source,
                 'codename': codename,
diff --git a/securedrop/tests/test_journalist.py b/securedrop/tests/test_journalist.py
index a677cae8e0..4f30da3fd9 100644
--- a/securedrop/tests/test_journalist.py
+++ b/securedrop/tests/test_journalist.py
@@ -18,6 +18,7 @@
 
 import crypto_util
 import journalist_app as journalist_app_module
+from journalist_app.utils import mark_seen
 import models
 from db import db
 from models import (
@@ -1847,11 +1848,11 @@ def test_delete_collection_updates_db(journalist_app, test_journo, test_source):
         source = Source.query.get(test_source["id"])
         journo = Journalist.query.get(test_journo["id"])
         files = utils.db_helper.submit(source, 2)
-        utils.db_helper.mark_files_seen(journo.id, files)
+        mark_seen(files, journo)
         messages = utils.db_helper.submit(source, 2)
-        utils.db_helper.mark_messages_seen(journo.id, messages)
+        mark_seen(messages, journo)
         replies = utils.db_helper.reply(journo, source, 2)
-        utils.db_helper.mark_replies_seen(journo.id, replies)
+        mark_seen(replies, journo)
 
         journalist_app_module.utils.delete_collection(test_source["filesystem_id"])
 
@@ -2074,9 +2075,7 @@ def test_download_selected_submissions_and_replies_previously_seen(
     db.session.add(seen_file)
     seen_message = SeenMessage(message_id=selected_submissions[1].id, journalist_id=journo.id)
     db.session.add(seen_message)
-    for reply in selected_replies:
-        seen_reply = SeenReply(reply_id=reply.id, journalist_id=journo.id)
-        db.session.add(seen_reply)
+    mark_seen(selected_replies, journo)
     db.session.commit()
 
     with journalist_app.test_client() as app:
diff --git a/securedrop/tests/test_journalist_api.py b/securedrop/tests/test_journalist_api.py
index cb8dcf0615..d113342bab 100644
--- a/securedrop/tests/test_journalist_api.py
+++ b/securedrop/tests/test_journalist_api.py
@@ -31,7 +31,7 @@ def test_unauthenticated_user_gets_all_endpoints(journalist_app):
 
         expected_endpoints = ['current_user_url', 'all_users_url',
                               'submissions_url', 'sources_url',
-                              'auth_token_url', 'replies_url']
+                              'auth_token_url', 'replies_url', 'seen_url']
         expected_endpoints.sort()
         sorted_observed_endpoints = list(response.json.keys())
         sorted_observed_endpoints.sort()
@@ -1039,3 +1039,127 @@ def test_revoke_token(journalist_app, test_journo, journalist_api_token):
         resp = app.get(url_for('api.get_all_sources'),
                        headers=get_api_headers(journalist_api_token))
         assert resp.status_code == 403
+
+
+def test_seen(journalist_app, journalist_api_token, test_files, test_journo, test_submissions):
+    """
+    Happy path for seen: marking things seen works.
+    """
+    with journalist_app.test_client() as app:
+        replies_url = url_for('api.get_all_replies')
+        seen_url = url_for('api.seen')
+        submissions_url = url_for('api.get_all_submissions')
+        headers = get_api_headers(journalist_api_token)
+
+        # check that /submissions contains no seen items
+        response = app.get(submissions_url, headers=headers)
+        assert response.status_code == 200
+        assert not any([s["seen_by"] for s in response.json["submissions"]])
+
+        # check that /replies only contains seen items
+        response = app.get(replies_url, headers=headers)
+        assert response.status_code == 200
+        assert all([r["seen_by"] for r in response.json["replies"]])
+
+        # now mark one of each type of conversation item seen
+        file_uuid = test_files['submissions'][0].uuid
+        msg_uuid = test_submissions['submissions'][0].uuid
+        reply_uuid = test_files['replies'][0].uuid
+        data = {
+            "files": [file_uuid],
+            "messages": [msg_uuid],
+            "replies": [reply_uuid],
+        }
+        response = app.post(seen_url, data=json.dumps(data), headers=headers)
+        assert response.status_code == 200
+        assert response.json["message"] == "resources marked seen"
+
+        # check that /submissions now contains the seen items
+        response = app.get(submissions_url, headers=headers)
+        assert response.status_code == 200
+        assert [
+            s for s in response.json["submissions"]
+            if s["is_file"] and s["uuid"] == file_uuid
+            and test_journo["uuid"] in s["seen_by"]
+        ]
+        assert [
+            s for s in response.json["submissions"]
+            if s["is_message"] and s["uuid"] == msg_uuid
+            and test_journo["uuid"] in s["seen_by"]
+        ]
+
+        # check that /replies still only contains one seen reply
+        response = app.get(replies_url, headers=headers)
+        assert response.status_code == 200
+        assert len(response.json["replies"]) == 1
+        assert all([r["seen_by"] for r in response.json["replies"]])
+
+        # now mark the same things seen. this should be fine.
+        response = app.post(seen_url, data=json.dumps(data), headers=headers)
+        assert response.status_code == 200
+        assert response.json["message"] == "resources marked seen"
+
+        # check that /submissions still only has the test journalist
+        # once in the seen_by list of the submissions we marked
+        response = app.get(submissions_url, headers=headers)
+        assert response.status_code == 200
+        assert [
+            s for s in response.json["submissions"]
+            if s["uuid"] in [file_uuid, msg_uuid]
+            and s["seen_by"] == [test_journo["uuid"]]
+        ]
+
+        # check that /replies still only contains one seen reply
+        response = app.get(replies_url, headers=headers)
+        assert response.status_code == 200
+        assert len(response.json["replies"]) == 1
+        assert all([r["seen_by"] for r in response.json["replies"]])
+
+
+def test_seen_bad_requests(journalist_app, journalist_api_token):
+    """
+    Check that /seen rejects invalid requests.
+    """
+    with journalist_app.test_client() as app:
+        seen_url = url_for('api.seen')
+        headers = get_api_headers(journalist_api_token)
+
+        # invalid JSON
+        data = "not a mapping"
+        response = app.post(seen_url, data=json.dumps(data), headers=headers)
+        assert response.status_code == 400
+        assert response.json["message"] == "Please send requests in valid JSON."
+
+        # valid JSON, but with invalid content
+        data = {"valid mapping": False}
+        response = app.post(seen_url, data=json.dumps(data), headers=headers)
+        assert response.status_code == 400
+        assert response.json["message"] == "Please specify the resources to mark seen."
+
+        # unsupported HTTP method
+        response = app.head(seen_url, headers=headers)
+        assert response.status_code == 405
+
+        # nonexistent file
+        data = {
+            "files": ["not-a-file"],
+        }
+        response = app.post(seen_url, data=json.dumps(data), headers=headers)
+        assert response.status_code == 404
+        assert response.json["message"] == "file not found: not-a-file"
+
+        # nonexistent message
+        data = {
+            "messages": ["not-a-message"],
+        }
+        response = app.post(seen_url, data=json.dumps(data), headers=headers)
+        assert response.status_code == 404
+        assert response.json["message"] == "message not found: not-a-message"
+
+        # nonexistent reply
+        data = {
+            "replies": ["not-a-reply"],
+        }
+        response = app.post(seen_url, data=json.dumps(data), headers=headers)
+        assert response.status_code == 404
+        assert response.json["message"] == "reply not found: not-a-reply"
diff --git a/securedrop/tests/utils/db_helper.py b/securedrop/tests/utils/db_helper.py
index c824de83ed..3e81e54b3b 100644
--- a/securedrop/tests/utils/db_helper.py
+++ b/securedrop/tests/utils/db_helper.py
@@ -4,6 +4,7 @@
 """
 import datetime
 import math
+import io
 import os
 import random
 from typing import Dict, List
@@ -12,7 +13,8 @@
 from flask import current_app
 
 from db import db
-from models import Journalist, Reply, SeenFile, SeenMessage, SeenReply, Source, Submission
+from journalist_app.utils import mark_seen
+from models import Journalist, Reply, SeenReply, Source, Submission
 from sdconfig import config
 
 os.environ['SECUREDROP_ENV'] = 'test'  # noqa
@@ -81,6 +83,9 @@ def reply(journalist, source, num_replies):
         reply = Reply(journalist, source, fname)
         replies.append(reply)
         db.session.add(reply)
+        db.session.flush()
+        seen_reply = SeenReply(reply_id=reply.id, journalist_id=journalist.id)
+        db.session.add(seen_reply)
 
     db.session.commit()
     return replies
@@ -148,7 +153,7 @@ def init_source():
     return source, codename
 
 
-def submit(source, num_submissions):
+def submit(source, num_submissions, submission_type="message"):
     """Generates and submits *num_submissions*
     :class:`Submission`s on behalf of a :class:`Source`
     *source*.
@@ -168,12 +173,21 @@ def submit(source, num_submissions):
     for _ in range(num_submissions):
         source.interaction_count += 1
         source.pending = False
-        fpath = current_app.storage.save_message_submission(
-            source.filesystem_id,
-            source.interaction_count,
-            source.journalist_filename,
-            str(os.urandom(1))
-        )
+        if submission_type == "file":
+            fpath = current_app.storage.save_file_submission(
+                source.filesystem_id,
+                source.interaction_count,
+                source.journalist_filename,
+                "pipe.txt",
+                io.BytesIO(b"Ceci n'est pas une pipe.")
+            )
+        else:
+            fpath = current_app.storage.save_message_submission(
+                source.filesystem_id,
+                source.interaction_count,
+                source.journalist_filename,
+                str(os.urandom(1))
+            )
         submission = Submission(source, fpath)
         submissions.append(submission)
         db.session.add(source)
@@ -192,38 +206,6 @@ def new_codename(client, session):
     return codename
 
 
-def mark_replies_seen(journalist_id: int, replies: List[Reply]):
-    """
-    Mark replies as seen.
-    """
-    for reply in replies:
-        seen_reply = SeenReply(journalist_id=journalist_id, reply_id=reply.id)
-        db.session.add(seen_reply)
-    db.session.commit()
-
-
-def mark_messages_seen(journalist_id: int, messages: List[Submission]):
-    """
-    Mark messages as seen.
-    """
-    for message in messages:
-        message.downloaded = True
-        seen_message = SeenMessage(journalist_id=journalist_id, message_id=message.id)
-        db.session.add(seen_message)
-    db.session.commit()
-
-
-def mark_files_seen(journalist_id: int, files: List[Submission]):
-    """
-    Mark files as seen.
-    """
-    for file in files:
-        file.downloaded = True
-        seen_file = SeenFile(journalist_id=journalist_id, file_id=file.id)
-        db.session.add(seen_file)
-    db.session.commit()
-
-
 def bulk_setup_for_seen_only(journo) -> List[Dict]:
     """
     Create some sources with some seen submissions that are not marked as 'downloaded' in the
@@ -247,9 +229,9 @@ def bulk_setup_for_seen_only(journo) -> List[Dict]:
         seen_messages = random.sample(messages, math.ceil(len(messages) / 2))
         seen_replies = random.sample(replies, math.ceil(len(replies) / 2))
 
-        mark_files_seen(journo.id, seen_files)
-        mark_messages_seen(journo.id, seen_messages)
-        mark_replies_seen(journo.id, seen_replies)
+        mark_seen(seen_files, journo)
+        mark_seen(seen_messages, journo)
+        mark_seen(seen_replies, journo)
 
         unseen_files = list(set(files).difference(set(seen_files)))
         unseen_messages = list(set(messages).difference(set(seen_messages)))