SAN JOSE -- In an unusually quick turnaround, the trial of a man accused of helping to kill his estranged wife 25 years ago will start in early September -- a scant six months after the man and his brother were arrested in the cold-case murder of the San Jose mother of two.

Homicide cases often take at least three times longer to get to trial. But David Zimmer, 66, of Half Moon Bay, told a Santa Clara County Superior Court judge Monday that he intends to invoke his legal right to a speedy trial, slashing the amount of time prosecutors have to prepare their case against him in the 1989 killing of his wife Cathy Zimmer.

Cathy Zimmer's strangled body was found in March 1989 in the back seat of her car at the San Jose airport, wrapped in a colorful patchwork quilt whose origins are still unknown despite widespread publicity.

The move is intended to force prosecutor Ted Kajani to either drop the murder charges or risk going to trial Sept. 8 with a weaker case than he might have if he had been able to keep investigating while David Zimmer remained locked up behind bars without bail.

"There is no substantial evidence showing that David Zimmer committed this," his lawyer, Michael Cardoza, contended Monday.

If Cardoza's strategy succeeds in forcing the Santa Clara County District Attorney's Office to drop the charges, the case could be refiled. But if a jury found David Zimmer not guilty, the case could not be tried again -- even if new evidence was discovered. Kajani declined to comment.

David's older brother, Robert Zimmer, of Santa Clara, also faces murder charges but will be tried separately, after David's trial. The strongest evidence the prosecution has publicly revealed so far implicates Robert. His DNA was allegedly found on the zipper or button of Cathy Zimmer's pants. But the prosecution alleges the two were partners in crime.

David Zimmer, who had left Cathy for another woman he married 10 years later, made $409,000 from the sale of their house and from insurance policies. Late last month, highly unflattering revelations about David Zimmer's conduct and character surfaced during his preliminary hearing. David Zimmer testified in February before a secret grand jury, and Kajani read part of the transcript into the preliminary hearing record.

David Zimmer admitted that Cathy Zimmer made him the beneficiary of her estate -- rather than her teenage children, only because she wanted to keep the money out of the hands of her ex-husband (their father), whom she despised. But she fully expected David Zimmer to take care of the kids, including her daughter, whom he had raised as his own since she was a toddler.

Instead, David Zimmer testified that he kept the money himself, buying such luxuries as a Maserati and a Ford Mercury Shelby, a collector's item even then. He also helped support his brother for 20 years, subsidizing his rent in what Kajani called an "arrangement." But Cardoza said Robert Zimmer worked for David Zimmer on his cars.

When Cathy Zimmer's daughter complained a few years later, he coldly told her in a letter that, "I took care of you and Mike because you were with your mom, not because you were wonderful children." Under close questioning by Kajani about his callousness toward the kids, David Zimmer asked him sarcastically, "Is that why we are here? You're here to evaluate me on a moral basis?"

Kajani also questioned David Zimmer about his habit of grabbing people by the back of the neck and squeezing -- in an apparent attempt to connect him to Cathy's strangulation. Zimmer claimed, "It isn't a painful gesture."

David Zimmer also denied having anything to do with an incident in which Cathy Zimmer complained one morning that her head hurt and vaguely recalled waking up during the night feeling as if an intruder was standing above her holding a hammer.

Contact Tracey Kaplan at 408-278-3482. Follow her at Twitter.com/tkaplanreport.