Prosecutors begin their rebuttal today in the penalty trial of Nikolas Cruz. Witnesses have been testifying about Cruz's antisocial behavior. The first detective spoke about swastikas seen on the rifle and combat boots he used the day of the shooting. Broward Sheriff's Detective Nicholas Masters testified about Cruz's hate-filled social media posts before the massacre. Prosecutors are expected to take the next two weeks challenging Cruz's attorneys who say he murdered seventeen people because he was born with fetal alcohol syndrome and had developmental issues ever since. The jury must decide if Cruz, who turned 24 on Saturday, should be be sentenced to death or life without parole.