Along with those killings, defendant Joseph Naso is being investigated for possible links to New York's "Double Initial Murders" -- killings in the early 1970s of three girls, each with matching initials.

During a hearing in Marin County Superior Court, Naso listened quietly as a judge detailed why representing himself would lower his chance of a successful defense.

Naso, 77, said he understood the pitfalls, but hiring the two or three attorneys he would need to defend a capital case would exhaust his resources.

"I don't feel anyone knows this case as well as I do," Naso said, sitting shackled in a red-and-white-striped jersey and red pants. "I've talked to three pretty good attorneys and have given this a lot of consideration."

Outside the courtroom, District Attorney Ed Berberian declined comment on Naso's statement about knowing the case but reiterated his belief that Naso has the financial means to hire counsel.

The four women killed in the 1970s and 1990s throughout Northern California all had matching initials Carmen Colon, Roxene Roggasch, Pamela Parsons and Tracy Tafoya. Investigators throughout the state and country are reviewing other cold cases for similarities.

The case against Naso, who was living most recently with his 49-year-old mentally ill son near Reno, Nev., was filed after authorities said they found an "enormous" amount of evidence while searching his home after a probation violation stemming from a theft conviction.

Judge Andrew Sweet said Thursday it was apparent that Naso was literate and understood the materials and questionnaire the court had given him as it determines if he will be allowed to serve as his own lawyer.

When Naso raised concerns about the cost of legal counsel, Sweet asked if he was choosing to represent himself because he cannot afford counsel.

"That's true," Naso said. "Having two or three attorneys I would need would exhaust my resources."

The judge replied, "I'm hearing enough from you regarding your financial situation that puts a question in my mind whether you have to represent yourself or want to represent yourself."

Prosecutors believe Naso has nearly $1 million in assets, and the public defender's office said it did not believe he would qualify as indigent.

The judge ordered Naso to discuss his concerns with the public defender's office and scheduled another hearing for Friday.