Karaivaz, who worked for a private TV channel, was shot several times on Friday outside his house.
Greek Prime Minister Kyriakos Mitsotakis has demanded the “swift resolution” of an investigation into a crime journalist’s murder that has already been condemned by leading European Union officials, political parties and media unions.
Giorgos Karaivaz, who worked for private TV station Star and also ran the news blog bloko.gr, was shot several times on Friday as he exited his car outside his house in the southern Athens district of Alimos after returning from work, witnesses said.
Police said Karaivaz, 52, was shot by two individuals on a motorcycle who fired multiple rounds. At least 12 bullet casings were collected from the scene, a police official said.
PM Mitsotakis summoned the police minister, Michalis Chrysochoidis, to a Saturday meeting on the case, the PM’s office said.
The murder was condemned by the European Commission and the Council of Europe commissioner for human rights.
“Murdering a journalist is a despicable, cowardly act,” European Commission chief Ursula von der Leyen tweeted on Friday.
Karaivaz had worked for some of Greece’s leading newspapers and TV channels in a 32-year career.
“[He] was one of the most experienced crime reporters in the field… and was held in high regard by colleagues,” the ESIEA union of Athens daily newspaper journalists said in a statement.
The federation of Greek police officers said Karaivaz was interested in improving working conditions for law enforcement and was “strongly critical of anybody” standing in their union’s way.
While Greek media offices are frequently targeted in firebomb and vandalism attacks, journalist killings are rare.
Some journalists request police protection after receiving threats, but Karaivaz was unguarded as he, according to local reports, did not ask for protection.
The shooting occurred at a time when Greek authorities had received criticism for allocating too many police guards to a controversial TV presenter.
In July last year, tabloid editor Stefanos Chios survived after being shot in the neck and chest by a hooded man outside his home.
The incident is still under investigation.
In 2010, radio manager, blogger and investigative journalist Socratis Giolias was gunned down outside his home. The case has not been solved.