ability to save him. >> reporter: prosecutors also suggest grasswald may have actually set him up to drown by tampering with his kayak's plug so the boat would fill with party. >> so your client didn't remove the plug from the victim's kayak? >> she did not. vincent left in his kayak on april 19th without the plug knowingly, has he had done several times in the past. >> reporter: in the days following the tragedy, grasswald posted this video of herself on facebook doing a cartwheel, along with smiling selfies, all of it raising eyebrows. she even showed up on stage at a local pub, singing "hotel california." a friend of the couple's described her performance as strange. mike coal vin issing an jellka grasswald's ex-boyfriend. >> did she have a temper? >> the temper would come out on occasion. as i told people there was no indication she was ever capable of anything like this. >> when they broke up in 2010 coal vin said grasswald made a