The Tennessee man who murdered his mom and best friend sent his brother $250 for “damages” afterwards, according to a new report.

Casey James Lawhorn, 23, penned a 1,000-word Facebook declaration detailing how he shot his mother, Vi Lawhorn, and pal Avery Gaines on Sunday. He then took off, sparking a day-long manhunt across multiple states that ended in rural Mississippi, where his body was found with a self-inflicted gunshot wound Monday morning.

His older brother, Chad Lawhorn, 28, told the Washington Post he woke up early the day of the murders to a Venmo transfer from his brother for $250 with a one-word note: “Damages.”

While still wearing his pajamas, he rushed to his mother’s house in East Ridge, Tenn., from his home in Nashville, and authorities there told him about the shootings.

“I’m still in shock,” he said. “People keep asking me how I’m feeling. … In my head, I don’t know what I feel. I don’t know how to feel. I don’t know what I need to do, and I don’t know what I need other people to do for me. … I feel myself drifting off.”

Investigators still don’t know why Casey Lawhorn committed the murders, but in his post he’d written: “I’ve spent a lot of time thinking about murder, wondering what it feels like.”

Chad Lawhorn said he doesn’t recognize the person who wrote the disturbing Facebook confession.

“That was not who I grew up with and who I talked to on a daily basis,” he said. “He took my mom and my brother from me.”

His younger brother didn’t have a criminal history or any previous incidents involving his family, he said.

“No one ever said he was a harm to anybody else. No mental-health professional ever indicated that,” Chad Lawhorn said.

Last year, Casey tried to overdose by shooting up heroin in the back of an abandoned church. The year before, while in college, he chased Percocet pills with alcohol, Chad Lawhorn said.

The older Lawhorn suspects his brother didn’t want to fail a third time, but can’t understand why he would also kill his friend and their mother.

His brother never owned a gun and believed in gun control, he said. He’d dropped out of Middle Tennessee State University after his first suicide attempt in 2016 and lived with his mom in a two-bedroom home she bought last year.

The brothers would watch Marvel and Star Wars films together as well as “The Daily Show” and went on road trips.

They shared political ideals and both volunteered to do field work for Democratic campaigns.

But Casey had recently felt pressure from his mother to get a job, Lawhorn said.

“I know he’d been frustrated lately. He’d been unemployed. There’s some tension with that. My mom was pushing him to get a job,” Chad Lawhorn said. “She was always super worried about him after the last two attempts. She couldn’t process the prospect of losing her baby.”