His younger brother, Casey James Lawhorn, transferred $250 to his Venmo account. Along with the money was a one-word note that, to Chad Lawhorn, instantly hinted at something terrible: "Damages."
Chad immediately thought his brother would harm himself, as he had done twice before, and the money was somehow a way to compensate for the emotional toll about to befall him. Casey, he said, had been suffering from severe depression and had stayed briefly at mental-health facilities. Sometime between two failed suicide attempts, Casey wondered whether the reason he was still alive was because he didn't have a gun, Chad said.
He arrived to see his mother's house surrounded by police cars, TV vans and crime scene tape. He stopped in the middle of the road and sat in his car for a few minutes, his mouth slightly open, when two officers approached him.
The news, Chad Lawhorn later learned, was far worse than he had feared.
His brother had shot and killed their mother and a close friend with a gun he had stolen, authorities said. Two officers told him that his brother had called 911 to report that he had killed his mother and his friend - and that he planned to kill himself.
"I think I'm still in shock. 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," Chad Lawhorn told The Washington Post.
Investigators have yet to say what they think drove Casey Lawhorn's rampage. East Ridge Assistant Police Chief Stan Allen said the 23-year-old didn't have any violent criminal history or any previous incidents involving his family.
The deaths come amid an intensifying debate about gun control and mental health in the United States. For Chad Lawhorn, a gun-control advocate, both issues hit hard as he struggles to find an explanation to his brother's sudden eruption of violence.
"No one ever said he was a harm to anybody else. No mental-health professional ever indicated any of that," he said.
Last year, Casey Lawhorn tried to overdose by injecting himself with heroin at the back of a secluded church before a police officer taking a break from patrol found him, his brother said. The year before, while in college, he chased Percocet pills with alcohol.
Chad Lawhorn said his brother had never owned a gun and shared his stance against guns. He can only assume that, perhaps, his brother didn't want to fail a third time. But why he also killed their mother, Vi Lawhorn, and his close friend, Avery Gaines, remains a mystery.
The brothers were five years apart and both attended Middle Tennessee State University. Chad Lawhorn studied international relations, and his brother, political science. But Casey Lawhorn dropped out after his first suicide attempt in 2016.
Still, Chad Lawhorn said he tried to distract his brother from his demons. They watched every Marvel and Star Wars film together. "The Daily Show" was one of their favorite TV shows, and they often talked about which jokes they liked the best. They also went on road trips, including one to Texas to visit friends.
Casey Lawhorn also volunteered at UnifiEd, a Chattanooga-based education advocacy group where his brother, now an independent political consultant, worked as a community organizer.
"Our team is shocked and heartbroken to learn of his actions. . . . We will work over the coming weeks to ensure that our staff, volunteers, and allies have the tools necessary to deal with this tragedy in a healthy way," the organization's interim executive director, Natalie Cook, said in a statement. "Our thoughts remain with Chad, his family, and our Hamilton County community during this difficult time of healing."
In recent years, as Casey Lawhorn cycled through different jobs, he had grown embittered, and his problems with depression worsened, according to his brother. He relied on his mother and lived with her in the two-bedroom house she bought last year. (The brothers' parents divorced in 2008).
"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."
Shortly before Casey Lawhorn killed himself, and as police pursued him, he posted what authorities said was a murder confession on his Facebook page. He described his mother's last moments in graphic and chilling detail, and how he kept shooting her until "it was over."
"She started screaming the worst scream I've ever heard," he wrote. "Movies really don't do justice to how true terror sounds."
He hinted at his plans: "Nothing happens after death, but if there is a hell, I'm going to be in the lake of ice at the bottom."
He talked about his brother, who he said would be hurt the most by his actions: "I'm sorry to him more than anyone."
Chad Lawhorn said he doesn't recognize the person who wrote those words.
"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."
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)