Prominent Greek criminal lawyer Stavros Georgiou was found beaten to death in his law office in central Athens, police said, in a case investigators believe was carried out by someone he knew.

Homicide detectives are examining his missing cellphone’s last signal and security camera footage from around his office building on Tritis Septemvriou Street, hoping to identify the killer.

There were no signs of forced entry, suggesting Georgiou knew his attacker.

Coroners Nikos Kalogrias and Symeon Mesogitis said Georgiou died from repeated blows to the head and chest from a blunt object; no stab wounds or gunshot wounds were found.

Investigators are considering whether the killer struck his head against furniture.