A handwritten letter penned by a then-16-year-old David Katz paints a disturbing picture of his relationship with his mother, nearly a decade before he opened fire on a Florida gaming tournament.
The scathing letter, penned by Katz in 2009 and obtained exclusively by Inside Edition, was sent it to the judge presiding over his parents’ divorce case and is part of the court file.
"I hate her more than anything in the world," he wrote about his mother. "I hate everything about her."
Katz had severe mental issues, and was treated at two mental hospitals as a teenager.
He also spent more than three months at a wilderness survival camp in Utah for troubled teens.
Katz was treated for schizophrenia with anti-psychotic and anti-depressant drugs, according to his parents' divorce papers.
"David would go days without bathing, would play video games until 4 a.m. on school nights, would walk around the house in circles," according to the judge who heard the divorce case.
Once, when his mother hid his game controller, he, “Punched a hole in her bedroom door.” Sometimes he would “curl up in a ball and sob.”
On Sunday, Katz, of Baltimore, Maryland, was at the "Madden NFL 19" event at GLHF Game Bar in Jacksonville when he opened fire, killing Eli Clayton, 22, and Taylor Robertson, 27, and wounding 11 others.
Katz then turned the gun on himself.
The 24-year-old was an elite player of the game, and was known by the tag name “Bread.” He was also known as “MrSlicedBread,” and “RavensChamp.”