OAKLAND -- A man sitting in a car was shot and killed Wednesday afternoon, the city's second homicide in three days.

Police said the victim, 20-year-old Malik Birchett, of Oakland, was in a car parked in the 600 block of 55th Street at 2:30 p.m. Wednesday when he was killed.

Police do not have a motive in the killing and had not made any arrests late Wednesday. It was the second slaying this week. A 17-year-old boy, Tyronta Mickens, was killed Monday afternoon at Hegenberger Road and Hamilton Street in the city's first homicide of the year.

A reward of $10,000 is being offered for any information leading to the suspect in the killing. Anyone with information can contact police at 510-238-3821 or Crime Stoppers at 510-777-8572 or 510-777-3211.

Follow Kristin J. Bender at Twitter.com/KJBender.