OAKLEY — A man who killed a teen and wounded three others in a house party here has been sentenced to 30 years in prison, records show.

Originally charged with murder, Sean Karp, 20, instead accepted convictions on charges of voluntary manslaughter and assault with a firearm, court records show. In exchange, he was sentenced to 30 years on Aug. 12, and sent to North Kern State Prison six days later.

The sentence resulted from a plea agreement between Karp and Contra Costa prosecutors. Karp was 18 at the time of the shooting.

The charges stem from a shooting that happened Oct. 21, 2023 during a house party on the 400 block of Shannon Way in Oakley. Ke’Marion Tucker, 16, of Brentwood, was killed. Three other teens were injured, two boys aged 17 and 15 at the time, and a then-17-year-old girl.

Four days later, police arrested a then-18-year-old Antioch man but promptly released him without charges. But police say the arrest shook loose information that helped them identify Karp as a suspect. He was arrested in December 2023.

Oakley police officers responded about 10:45 p.m. the night of the shooting to a noise complaint at the home where the party took place. They left after an 18-year-old woman who lived there declined an offer to help break up the party, Oakley Police Chief Paul Beard said in previous statements. Shortly after police left, the party turned violent and several shots were fired in front of the home, police said at the time.