Is a serial killer with a knife on the loose in SF?

Signs of a serial killer in San Francisco?
De la Plaza was found dead in his Hayes Valley apartment. Di Martino was found dead in his Lower Haight apartment on Hermann Street.

That’s the question Melissa Nix, ex-girlfriend of Hugues de la Plaza posed, on reading in the Examiner that Philp DiMartino, 36, had been found dead from multiple stab wounds inside an apartment in San Francisco.
It’s definitely a scary thought—one that Nix kept raising when she was fighting with the San Francisco Police Department over de la Plaza’s cause of death. The San Francisco Medical Examiner initially ruled that de la Plaza’s cause of death was “undetermined.”
But Nix, who challenged the notion that de la Plaza would ever have killed himself, kept worrying that de la Plaza had been murdered—and that his killer was still on the loose, and possibly walking the streets of San Francisco.
In February, de la Plaza's father announced that the SFPD was now considering the case as a murder. And Nix uncovered another forensic report that supported her belief that her ex had been stabbed by someone else.

Either way, the two men certainly died in close proximity to one another: de la Plaza's apartment was on Linden Street, Martino's was at 138 Hermann Street.