Greek police have arrested five people over the killing of a University of California at Berkeley professor who was shot dead in an Athens suburb earlier in July, police said.

Przemyslaw Jeziorski, who taught quantitative marketing at the Haas School of Business, was shot several times on July 4 outside Athens, the authorities said.

A UC Berkeley professor was gunned down in an Athens suburb just a day after a custody hearing—now, Greek police have brought his ex-wife and four others in for questioning as they probe what they say appears to be a contract killing,