FRESNO, Calif. (KFSN) -- Confessions, video, and witnesses prove Kori Muhammad killed four people.But now that he's on trial, his state of mind may be more important.The death penalty is on the line in Fresno County for the first time since 2013 because the defendant killed four people and prosecutors say he picked his last three victims on the basis of race.But his defense attorneys say the man just snapped because of severe mental health issues."This case is about the senseless murder of Carl Williams III as well as the cold, calculated and racist murder of Zachary Randalls, Mark Gassett, and David Jackson," prosecutor Kelly Smith told the jury.Smith is building a capital murder case with the killer's own words acting as bricks."He made several statements which included 'I did it. I shot them,'" Smith said.The foundation of the case may be surveillance video from the April 2017 shooting at a Motel 6.It clearly shows the defendant walking away from security guard Carl Williams and then launching a sneak attack, pulling his gun, turning back to Williams, and firing several shots before trying to shoot his emptied gun at another security guard up the stairs.Police say the shooter disappeared for a few days, but when he saw himself on the news as the suspect, he decided to kill as many white men as he could before he got arrested.He killed three of them as he walked towards downtown Fresno and then confessed to the officers who arrested him.But his defense attorney says it wasn't a racist killing spree. It was a man with a severe mental illness suffering a violent breakdown."You're going to hear evidence that suggests he was going to the Fresno Police Department on the 18th to turn himself in when on his way to the department he saw a PG&E truck," said Richard Beshwate. "You're going to hear evidence about why PG&E was a trigger."More than a dozen of the victims' family members attended Day One of the trial, hoping justice can wallpaper over the pain of these last three years."Then hopefully we'll have closure, and we can just go on," said Rosie Wagner, Mark Gassett's mother.The trial could last a couple of months because it could have three phases: guilt and sanity, and then -- if they find him guilty and sane -- punishment, which could lead to the death penalty.