She did assert that yes, and it was based on the notion that there was a video from the church at which he dropped Maddie off at. However, it is presently unclear whether there was such a video from the church parking lot at all, or whether it showed someone else (it was said to be grainy). JS said she hadn't been allowed to see the video. She said her sister was "at location" and she said LE were telling her what they saw on the video.
Sometimes I think the information we get is sideways from presplaining.
Speculation:
For example, SS tells LE he dropped MS off at school.
LE says, that's funny, we see your car drive right past the school.
SS pivots. That's right. I just remembered I dropped her off somewhere else. She was sleeping but also somehow asked me to.
So now dropping her off by the church becomes a new version of the not-truth.
I recall another case, clearly investigated as a murder of a child but labeled missing person, where video existed of a completely unconnected boy across town, and the POI jumped on it, to deflect.
I just note that as LE investigates crimes like this, as they expose POI lies, the POIs are often quick to supply a new lie.
Swirling eddy of ugly lies here.
I applaud the fast action by LE in collecting cctv in this case. The primary PPI is apparently as dumb as he is evil and digital forensics will do him in.
JMO