Transcript for New Details in Gunman's Sinister Plan
We begin with major developments. That tragedy on TV, chilling new details about the mind of a monster, the gunman ambushing two young journalists, determined to murder his former colleagues in cold blood. As the cameras rolled, this image, one of the last they would see. Tonight what investigators discovered inside his car, a wig, a to do list and a stock pile of ammo. Was he planning an escape? Inside that newsroom, a motel of silence. What they're now revealing, why they thought the gunman was coming for them next. ABC's Pierre Thomas leading our team coverage tonight. Reporter: Vester Flanagan committed suicide after killing his former colleagues. But newly discovered items suggest he may have wanted to avoid authorities. Police find a black hat and plea additional license plates along with a 9 millimeter clock pistol. The former TV reporter who would kill his former co-workers in cold blood on live television by his own accounts was a brooding, ticking time bomb. His broadcast career long marked by struggle, with Flanagan repeatedly in the role of mall content, often flashing with colleagues, claiming to be the victim. In 2014 Flanagan filed a lawsuit against WDBJ again claiming racial discrimination and sexual harassment, allegations the station denied. I'm going to make you pay, I'm going to tell them that you sexually harassed me. I said do you know that's a lie and I hung up the phone. Reporter: In memos to the court, they described Flanagan as the problem. In a may 2012 memo, managers wrote, you lost your temper and used verbal and body language that left co-workers feeling both threatened and extremely uncomfortable. The station ordered him to get counseling before eventually firing him. The anger was simmering. In a recent suicide note Flanagan wrote of continued frustrations, that he gave up looking for a job because I don't need to deal with workplace bullies anymore. It looks to me that he had a severe mental illness. I say that because he appears to be delusional at times. He's clearly paranoid. Reporter: The tipping point, he said, was the racially motivated Charleston Chuh shooting, killing black parishioners. He put down a deposit on a pistol two days later. He said he wanted to kill to start a race war.
This transcript has been automatically generated and may not be 100% accurate.