An Idaho teenager, aged 16, admitted guilt in the fatal shooting of a woman, claiming his actions were driven by her refusal to give him a ride and suspicions about her brothers’ involvement in his friend’s death.

The suspect, Bobby Grant Jackson Jr., allegedly confessed to the police, saying, “I put a bullet in her brain,” referring to the victim, 30-year-old Rebecca Rivera.

Jackson entered a guilty plea to second-degree murder for the incident on October 23, 2025, in Blackfoot, which is about 250 miles east of Boise, according to court documents. In a plea agreement, prosecutors agreed to drop the first-degree murder charge. As reported by EastIdahoNews, the deal proposes a prison term ranging from 20 to 27 years. His sentencing is scheduled for March 4.

Previously reported by Law&Crime, Rivera’s family discovered her lifeless at around 4 p.m. with a gunshot wound in her mobile home located on the 1100 block of Broadway Street.

Details from a probable cause affidavit, accessed by Law&Crime, revealed that Jackson was employed by a subcontractor working on a hospital renovation earlier that day. An employee recounted that Jackson requested a restroom break but was absent for an extended period. Upon searching for him, the employee noticed that a handgun, previously kept in a lunch box inside his truck, was missing, and Jackson was also gone, prompting a call to the police.

Police reviewed surveillance footage, which captured Jackson entering the truck and taking an item. Following up with the gun owner, detectives collected ammunition identical to that which was reportedly in the stolen firearm, as the Idaho State Journal highlighted. A comparison of the bullets revealed a match with the shell casing found at Rivera’s residence, according to police reports.

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 the day after the murder at a home in Pocatello. Cops say Jackson had “no known relationship” with Rivera. EastIdahoNews obtained an amended complaint that contained Jackson’s interview with detectives.

Investigators reportedly wrote that Jackson asked Rivera for a ride and when she said no, 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.