Police arrested on February 7 a man, suspected of planting a hand grenade that killed Yuri Vazagashvili, deputy chief prosecutor announced on Sunday.

Suspect is a policeman from Tsalka municipality, who denies charges, Irakli Shotadze, deputy chief prosecutor told journalists.

Yuri Vazagashvili was killed on January 20 by a hand grenade planted at a grave of his son, Zurab Vazagashvili, who died in a police operation in 2006. Yuri Vazagashvili campaigned for punishment of police officers involved in the operation in which his son and another man died. 11 former and current police officers were arrested and charged with “premeditated murder” in connection to 2006 operation on February 2.

Deputy chief prosecutor Shotadze said on February 8 that investigators were able to identify and arrest suspect in murder of Yuri Vazagashvili with the help of DNA sample found on one part of the hand grenade, which went off at the grave.

“That was a mistake of a killer and we were lucky,” Shotadze said, adding that investigators had “incontrovertible evidence” against the arrested individual.

He declined at this stage to speak about possible motives of the crime, saying that the investigation was still ongoing.

PM Irakli Garibashvili, who is now at the Munich security conference, welcomed “prompt” investigation of the case.

“It was an important challenge for our government. The fact that it was promptly investigated is a source of pride for me and I want to congratulated and thank everyone, who were involved in the investigation,” PM Garibashvili told Georgian journalists in Munich.