SAN FRANCISCO » A jury has found a 79-year-old former photographer guilty in the decades-old killings of four California women.

After deliberating for less than eight hours, the Marin County Superior Court jury on today found Joseph Naso guilty of killing two young prostitutes in the 1970s and two others in the 1990s.

Naso acted as his own attorney in the two-month trial in which prosecutors presented DNA and other compelling evidence against him. Marin County deputy public defender Pedro Oliveros assisted Naso and confirmed the Reno, Nev., resident was convicted of four counts of first-degree murder.

The four victims all had alliterative initials in their names. The same jury will reconvene Sept. 4 for the penalty phase of the trial. Prosecutors are seeking the death penalty.