diff --git a/tests/test_focus_estimator.py b/tests/test_focus_estimator.py
index c3cca07..b5c3997 100644
--- a/tests/test_focus_estimator.py
+++ b/tests/test_focus_estimator.py
@@ -38,21 +38,26 @@ def test_focus_estimator(tmp_path):
 
     plot_path = tmp_path.joinpath("test.pdf")
     data3D = np.random.random((11, 256, 256))
-    slice = focus.focus_from_transverse_band(
+    slice, stats = focus.focus_from_transverse_band(
         data3D, NA_det, lambda_ill, ps, plot_path=str(plot_path)
     )
     assert slice >= 0
     assert slice <= data3D.shape[0]
     assert plot_path.exists()
+    assert isinstance(stats, dict)
+    assert stats["peak_index"] == slice
+    assert stats["peak_FWHM"] > 0
 
     # Check single slice
-    slice = focus.focus_from_transverse_band(
+    slice, stats = focus.focus_from_transverse_band(
         np.random.random((1, 10, 10)),
         NA_det,
         lambda_ill,
         ps,
     )
     assert slice == 0
+    assert stats["peak_index"] is None
+    assert stats["peak_FWHM"] is None
 
 
 def test_focus_estimator_snr(tmp_path):
@@ -80,7 +85,7 @@ def test_focus_estimator_snr(tmp_path):
             ps,
             plot_path=plot_path,
             threshold_FWHM=5,
-        )
+        )[0]
         assert plot_path.exists()
         if slice is not None:
             assert np.abs(slice - 10) <= 2
diff --git a/waveorder/focus.py b/waveorder/focus.py
index 709be23..5aa806e 100644
--- a/waveorder/focus.py
+++ b/waveorder/focus.py
@@ -52,6 +52,8 @@ def focus_from_transverse_band(
             return the index of the in-focus slice
         else:
             return None
+    peak_stats : dict
+        Dictionary with statistics of the detected peaks, currently 'peak_index' and 'peak_FWHM'.
 
     Example
     ------
@@ -62,6 +64,7 @@ def focus_from_transverse_band(
     >>> in_focus_data = data[slice,:,:]
     """
     minmaxfunc = _mode_to_minmaxfunc(mode)
+    peak_stats = {'peak_index': None, 'peak_FWHM': None}
 
     _check_focus_inputs(
         zyx_array, NA_det, lambda_ill, pixel_size, midband_fractions
@@ -72,7 +75,7 @@ def focus_from_transverse_band(
         warnings.warn(
             "The dataset only contained a single slice. Returning trivial slice index = 0."
         )
-        return 0
+        return 0, peak_stats
 
     # Calculate coordinates
     _, Y, X = zyx_array.shape
@@ -95,9 +98,10 @@ def focus_from_transverse_band(
 
     peak_results = peak_widths(midband_sum, [peak_index])
     peak_FWHM = peak_results[0][0]
+    peak_stats.update({'peak_index': peak_index, 'peak_FWHM': peak_FWHM})
 
     if peak_FWHM >= threshold_FWHM:
-        in_focus_index = peak_index
+        in_focus_index = int(peak_index)
     else:
         in_focus_index = None
 
@@ -112,7 +116,7 @@ def focus_from_transverse_band(
             threshold_FWHM,
         )
 
-    return in_focus_index
+    return in_focus_index, peak_stats
 
 
 def _mode_to_minmaxfunc(mode):