i don't know what time rebecca zahau died. s at the hospital all night. >> in 2013 keith greer filed a civil wrongful death lawsuit on behalf of the zahau family. based on his eyewitness, he named dina as a defendant. along with her twin sister nina. there was also a third defendant, the man who called 911, jonah's brother, adam shacknai. >> did you have anything to do with rebecca's death? >> absolutely not. >> greer disagreed. he pointed to those knots tied around rebecca's wrists and ankles. >> figuring them out in the first place is really hard. tying them, almost impossible. >> greer believed whoever tied the knots had to be an expert, possibly a sailor. and adam shacknai worked on the mississippi river as a tugboat captain. >> when he ties things off, he uses a figure 8 and then closes it with a single hitch or two. guess what knots are tied on both her legs and her hands. figure 8s, tied off with a single hitch or two. >> sheriff's investigators had questioned adam extensively after rebecca's death. >> you didn't hold an