According to police, the suspect in Sunday's shooting at Royal Car Wash turned himself in around 10 p.m. Monday.
La'Melvin Johnson, 35, surrendered outside of the Harris County Jail with community activist, Quanell X.
Johnson was transferred to the Fort Bend County Jail later Monday night.
"[Johnson] said there was some confrontation at the detail shop, but it had nothing to do with being fired," Quanell X said. " [Johnson] said this was an ongoing dispute involving other things, and that there was no intention to come up to the shop and kill anyone, but there was a confrontation at the shop. He says it was self-defense."
The shooting happened around 10:15 a.m. Sunday at Royal Wash Mobile on Avenue E and Main. According to the Stafford Police Department, one person died at the scene and two others were rushed to the hospital, where they later died.
The victims have been identified as employee Donntay Borom, 18, business owner Harvey "Troy" Simmons, 34, and Simmons' uncle, Johnny Simmons, 59.
According to investigators, Johnson became irate after getting terminated from the business and an argument ensued.
"During the argument he went to his vehicle and that's where he apparently got his gun and came back and opened fire," said Sgt. James Leedom with the Stafford Police Department.
Harvey Simmons' wife told Local 2 her husband did mention a problem with Johnson in a text message a few days ago.
"He did text me a couple of days ago that he was having problems with him," she said. "He didn't give me details... I wish I would have asked more now."