Police in Greece are searching for the killer of a University of California Berkeley professor who was shot and killed on July 4 while visiting Athens to see his children and attend a family custody hearing.

A marketing professor at the University of California, Berkeley has died, reportedly after being gunned down by a masked gunman while visiting Greece earlier this month.

Przemyslaw Jeziorski, a native of Poland who taught at the Haas School of Business at UC Berkeley, was shot on July 4 in Agia Paraskevi, a suburb of the Greek capital of Athens, Greek outlet Ta Nea reported, citing Hellenic Police’s accounts.