Robin Westman, 23, has been identified as the gunman behind Wednesday’s deadly shooting at a Catholic church in Minneapolis. Authorities say he left behind disturbing online videos and a handwritten journal suggesting violent motivations.

Hours before the attack, Westman posted a 20-minute YouTube video titled “So long and thanks for all the fish.” In it, he flipped through a red spiral notebook filled with fantasies of violence, including passages praising Sandy Hook killer Adam Lanza. One chilling line read: “Mass murder has been on my mind for a while.”

Westman’s writings revealed an obsession with mass murderers. He fantasized about “being that scary horrible monster standing over those powerless kids” and admitted his desire to cause “devastating tragedy.” His mother had worked at Annunciation Catholic School until 2021, giving him a personal connection to the target.

In another video, he displayed firearms and magazines scrawled with phrases like “where is you God?” and “for the children.” Police say he used three weapons in the attack—a rifle, a shotgun, and a handgun—while blocking exits with wooden planks to trap victims.

His journal showed detailed planning. He wrote about analyzing crowd sizes and considered attacking children at recess before settling on a church service. On Wednesday, he opened fire through stained-glass windows at children gathered inside the sanctuary.

According to Minneapolis Police Chief Brian O’Hara, Westman died from a self-inflicted gunshot wound. Two children, ages 8 and 10, were killed, while 17 others—14 children and three adults—were injured.

Court records show that in 2019, he changed his name from Robert to Robin. He had no criminal record and was previously unknown to law enforcement. Investigators are still piecing together his motives.

Raised in a quiet neighborhood in Richfield, Minnesota, Westman’s calculated and violent act has left the local community reeling and the nation in shock.