Dallas police have made more arrests as a result of the investigation into the shooting death of 18-year-old Oziel Garcia.

Garcia was shot and killed outside the front door of the apartment he shared with his parents and three siblings early on Tuesday.

Police say the suspects robbed the recent high school graduate of his red 2008 Chevy Silverado pickup truck. His credit cards were also used, according to investigators.

Kristi Starrett, 32, and her boyfriend, Deavian Hill, 26, were arrested on Saturday. Police said Starrett admitted to using the victim's credit cards. Hill was jailed on a capital murder charge, according to police.

Earlier, witnesses led police to a juvenile person of interest. According to Dallas police, the 15-year-old implicated himself and was arrested for capital murder.

Oziel Garcia had just returned home to 3330 Webb Chapel Extension in Dallas from watching fireworks at Kaboom Town in Addison on July 4.

Isaar Garcia says his brother didn't have any enemies.

"He just had his friends from school, no one else," Garcia said. "They actually took an innocent life away just to take a truck."

DPD released surveillance video on Wednesday showing two males believed to be responsible for the carjacking and murder.

DPD released surveillance video showing two suspects believed to be involved in the fatal carjacking of Oziel Garcia, 18, early on Tuesday July 4, 2017.

On Thursday, DPD sources told WFAA a manhunt was underway for a capital murder suspect in the 7700 block of Ferguson Road.

Officers took away several juveniles that from the complex that face "various charges in relation to the investigation", according to DPD.

Most importantly for Isaar Garcia, police found his brother's stolen pickup truck. He's hoping it will bring more answers as to what led up to someone targeting his brother.

"I’ll just leave it all in God’s hands," Garcia said. "God will know what to do with them.”