An Idaho teenager, Bobby Grant Jackson Jr., aged 16, faces charges of first-degree murder following the fatal shooting of a woman in Blackfoot. The incident reportedly occurred after Jackson allegedly stole a firearm from his workplace. Authorities say Jackson shot 30-year-old Rebecca Rivera because she refused to give him a ride and he suspected her brothers were involved in his friend’s death.

Jackson allegedly confessed to the crime, telling police, “I put a bullet in her brain,” referring to Rivera. The tragic event took place on Thursday, approximately 250 miles from Boise. Family members discovered Rivera’s body with a gunshot wound at her mobile home located in the 1100 block of Broadway Street around 4 p.m.

According to a probable cause affidavit accessed by Law&Crime, Jackson was employed by a subcontractor involved in hospital renovations on the day of the incident. An employee reported Jackson’s prolonged absence after he asked to use the bathroom. Upon searching for him, the employee noticed a handgun was missing from his lunch box inside his truck, prompting him to contact the police.

Police reviewed surveillance footage revealing Jackson entering the truck and taking an item. Further investigation indicated Jackson had been residing in a halfway house and was on probation following a prior armed robbery arrest. A halfway house employee informed police that Jackson’s phone was traced to a gas station on the 900 block of Broadway Street, close to the scene of the crime.

Officers obtained surveillance footage that showed Jackson enter the truck and grab something. Investigators learned that Jackson had been living at a halfway house while on probation from a previous arrest for armed robbery. An employee at the halfway house told cops Jackson’s phone showed he was at a gas station in the 900 block of Broadway Street, which is just down the street from the murder scene.

Detectives spoke with Rivera’s neighbors who said they saw Jackson earlier in the day asking for a ride. Surveillance images confirmed he was at the trailer park sometime after 12:40 p.m. Investigators also found that Rivera was murdered with a 9 mm handgun — the same type of weapon that Jackson allegedly stole from the worksite.

An arrest warrant was initially obtained for second-degree murder, and cops took Jackson into custody Friday at a home in Pocatello. Cops say Jackson had “no known relationship” with Rivera. Local news website EastIdahoNews.com obtained an amended complaint that contained Jackson’s interview with detectives.

Investigators reportedly wrote that Jackson asked Rivera for a ride and when she declined, he said “f— it” and went into the trailer and killed her. He also claimed that he recognized Rivera and “believed her brothers had killed his friend,” the affidavit reportedly said. When asked if he killed Rivera as payback, he reportedly answered in the affirmative.

“I put a bullet in her brain,” he allegedly said.

After his interview, prosecutors upgraded the charge to first-degree murder. He’s being charged as an adult.

Jackson is being held at the 3B Detention Facility on a $1 million bond. His next court date is slated for Nov. 6.