GARLAND, Texas (CBSDFW.COM) – An arrest affidavit regarding the triple murder at a Garland gas station convenience store on Dec. 26 suggests the deadly shooting of three teenagers was in response to a shooting the month before.

One of the victims in the shooting said he and some friends were shot at by another group of juveniles on Nov. 19, the redacted affidavit states.

An attorney for a man accused of driving his son to a Garland gas station where the 14-year-old is accused of fatally shooting three teens and wounding a fourth spoke out Tuesday.

“We believe that Abel Acosta is the son of the driver of the Dodge truck, Richard Acosta,” Garland Police Lt. Pedro Barineau said nearly a week ago.

“I believe the evidence will show he was about to leave, but the son wants to go in and get something and unbeknownst to him, he didn’t know he had a gun,” attorney Heath Harris said.

Harris is representing 33-year-old Richard Acosta Jr. who faces a capital murder charge, said his client did not know his son was the alleged shooter.

Richard Acosta Jr. (credit: Garland PD)

“At the time of the shooting he didn’t know who was shooting,” Harris said. “He was just trying to get himself and his son out of there.”

Garland police said 14-year-old Abel Elias Acosta shot and killed three teenagers on December 26.

They said Acosta Jr. was the getaway driver for his son.

Harris said when his client asked his son what happened, and his son did not answer and took off in his truck.

He said during his own search for his son he found police were looking for him and decided to turn himself in.

CBS 11 asked Harris if Acosta knows where his son is right now.

“Absolutely not, absolutely not, no he doesn’t know. First of all, he’s in jail,” Harris said.

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Despite what the attorney Harris says, the families of the three teenagers killed continue to echo what they said last month.

“We want him to get caught, we want him to pay for what he did,” Xavier Gonzalez’s Aunt Erica Gonzalez said.

CBS 11 reached out to one of the families of the teen victims Tuesday, but they did not want to speak on camera about what Acosta’s attorney said.

Alexis Wainwright