Dov Tagar, who on Monday allegedly murdered his lifelong partner, Hatuella Koznizov, her son Alex and his friend Yosef Dov before killing himself, was jealous of Koznizov for her contact with other men, police said Tuesday.

The four were killed in the Haifa area Monday in what police suspect was a triple murder and suicide.

According to testimony received Monday night, Koznizov had warned that Tagar was trying to control her, even ordering her to cut off all ties with her close friends and acquaintances.

Tagar had not mentioned Yosef Dov by name, though, and a police commander made it clear that no complaint had been filed against the alleged killer.

Tagar, a security guard with no prior record, was thought to have stabbed Koznizov, 40, and her son, 17, to death in his Kiryat Shmuel apartment. Later that day, he allegedly gunned down Dov in an elevator in the industrial area in Kiryat Hayim. In the evening, he shot himself in plain view of police.