man didn't do anything on purpose. >> the prosecution started off in dramatic fashion. they played lars' 911 call for the jury. as the tape rolls, lars shook and sobbed with his entire body. once again, the prosecution wondered, was it real remorse? smr i have small children. i have seen that face before. it usually involves just before a dirty diaper. >> that's a first on "dateline." >> he had that expression of bearing down, turning red. you never saw a tear. >> next up the first officer on the scene that night. he testified that lars didn't look like a man who had been doing cpr open his mortally wounded wife. >> he was clean. >> what do you mean by clean is this. >> he didn't have any blood on his body. once they saw him doing cpr, then he had blood on his hands. >> detectives told the jury lars put on an emotional display.