but even as she helped search for vince viafore's body, her behavior struck some as strange. as the river. vince's mother, mary ann. >> she wasn't sitting there crying, that's for sure. i don't know. she just went about her business. >> reporter: business like posting a light-hearted video, doing a cartwheel. >> woo! yay! >> reporter: and five days later, at a memorial gathering at a bar, breaking out in a karaoke version of "hotel california." ♪ in the hotel california >> reporter: but that was nothing compared to what police say angelika did 10 days after vince disappeared in the river. she had taken flowers to bannerman's island for vince. detectives follow. one of them claims angelika takes him aside and blurts out a jaw-dropping confession. she wanted vince to drown. she pulled the drain plug on his kayak so it would fill with water and sink and removed a ring connecting the two halves of his paddle. but none of that alleged confession was recorded. so police bring angelika to the barracks. at 3:25 in the afternoon, they lead her to the interrogation room, and the unblink