MARTINEZ, Calif. — Murder defendant Susan Polk's expert witness Dr. John Cooper has flown the coop.

"He is indicating not only is he not going to return, but he will be unavailable by telephone for this week and he will be traveling," Judge Laurel Brady announced Monday morning during a hearing outside the presence of the jury.

"In all the years that I've been doing this ... I have never heard of anything like this before or even something close to it," Brady said. "I've never had an expert witness take on the role of an advocate and then indicate he has chosen not to come back — that is just not an option."

Cooper, a retired forensic pathologist from Texas, informed the judge in a three-page e-mail, dated May 7, of his decision not to return, "in view of the hostile behavior of the prosecuting attorney following my testimony on Thursday."

In his letter, which was made available to the public late Monday, Cooper told Brady that it was a "privilege to appear in your courtroom," but he blamed the prosecutor and the county's forensic pathologist for his decision to withdraw from the case.  

Story continues

The judge ordered Cooper to return, however. The witness was reached by phone and the parties agreed he would return May 16 to complete cross-examination.

Brady told the jury Monday morning that a scheduling issue had interrupted the witness's testimony.

In his letter, Cooper accused the "clever" prosecutor, Assistant District Attorney Paul Sequeira, of "provoking a mistrial," and creating "a dramatic smokescreen about some discovery issues that have no bearing on the physical evidence and certainly have nothing whatsoever to do with the fact that an innocent woman is being held on false charges."

"I've never seen an expert run off like a scared rabbit before he is cross-examined," Sequeira said after reviewing the letter Monday morning.

Cooper also accused the county's forensic pathologist, Dr. Brian Peterson, of "irresponsible, unprofessional and ... immoral conduct."

"I consider this man to be nothing less than a public menace," Cooper wrote.

Peterson performed an autopsy on the victim, 70-year-old psychologist Felix Polk, and testified that he died from blunt-force trauma to his head and the 27 stab wounds inflicted on him by his wife in October 2002.

Polk, 48, is representing herself in her first-degree murder trial and claims she acted in self-defense during a struggle for the knife.

Cooper testified last week that, based on his review of the evidence, Polk acted in self-defense and Felix died from a heart attack in the middle of beating his wife.

Cooper said he relied on such material as the autopsy report, crime scene photos and Polk's own letters in which she described the incident and drew a diagram.

When asked to produce the letters, Cooper testified that he didn't have them, but told the judge they might be in his motel room. On Friday he returned to court and said he lost them on the plane or someone stole them from his motel room, or perhaps they were in his office in Texas, but no one was available to look for them. The judge ordered Cooper to return to court Monday for cross-examination and to bring his entire case file from Texas.

"The only thing he didn't say was that the dog ate the defendant's letters," Sequeira said.

Polk accused the judge of assisting the prosecution in creating a "contrivance" about discovery issues to delay her case.

"I move for a mistrial based on judicial misconduct and prosecutorial misconduct," Polk said.

Her mistrial motion, one of dozens since trial began March 7, was denied.

Polk flipped through her files, took notes on a legal pad, and did not acknowledge Brady as she made her ruling.

"Frankly, I'll be very honest," Brady told the defendant. "For him to do this to you in the middle of testimony is — I'm looking for the right word — it is bizarre and inexcusable."