. >> reporter: retired agent doug merel stood by him as well. he's the man who first hired art at the fbi academy. >> do you think they had enough to go on, the commonwealth, to ing >> i was -- >> -- these charges? >> -- very, very surprised when an indictment was handed up. it's a clear case of self-defense. >> reporter: his former colleague and sister were by art's side as his trial began in march 2014. they all listened as prosecutors made their case that art gonzales was a liar and a murderer. >> he was trying, from the beginning, to paint a portrait of self-defense. and we knew a large part of that portrait was a lie. >> reporter: the prosecutors told jurors how on the day of the shooting, they believed the fbi agent was emotionally unstable. driven by that breakup with his girlfriend. >> it was an obsessive, deeply romantic relationship. and that was the context for what happened in the house that day. >> reporter: they laid out in court their theory of a man fueled by rage. one who murdered his wife, then staged the scene to look like sel