Witness Isn’t Positive on Tire Tracks : Murder trial: But prosecutor says impact on case against man accused of killing his wife may not be great.

A key prosecution witness testified that tire tracks found near the body of a murdered La Canada Flintridge woman could have been made by her husband’s car, but he admitted under cross-examination that he couldn’t tell for sure.

Peter McDonald, 61, a retired Firestone Tire & Rubber Co. tread designer from Hudson, Ohio, was called to link Donald Miralle’s Chevrolet Suburban with tire tracks left in the desert near Victorville, where the body of Miralle’s wife, Tessie, was found last year.

McDonald told the six-man, six-woman San Bernardino Superior Court jury last week that wear patterns on the outside edge of one tire of the Suburban matched wear patterns in photographs taken of tracks near Tessie Miralle’s body.

But defense attorney A. Brent Carruth, during a full day of cross-examination, maneuvered McDonald into admitting that he had not found an accidental cut or gouge, the kind of unique characteristic McDonald said he needed to positively identify the tire.

In a book he wrote on tire track identification, McDonald said at least one such characteristic is needed to positively match a particular tire to a particular imprint.

McDonald told Deputy Dist. Atty. Elizabeth Elwood that he believed the tire track photographed in the desert was “the same as” an ink impression, made from Miralle’s tire, that McDonald examined in Ohio.

The prosecution closed its case Monday in the trial, which began last month and is expected to end in November. Authorities contend that Miralle, 47, strangled his wife on Sept. 12, 1990, then abandoned her burning body alongside a dirt road 15 miles northwest of Victorville.

Attorneys for Miralle, a civil engineer in Pasadena, have so far focused on inconsistencies within the prosecution’s case, while also suggesting that others--including some people who owed her money--had a motive to kill Tessie Miralle, 49.

Though Elwood at first said she worried about the effect Carruth’s grilling of McDonald would have on the prosecution case, she said Tuesday that the impact may not have been as great as she had thought.

Elwood pointed to Miralle’s actions after his wife’s disappearance and right up to his trial. Citing his calm courtroom demeanor, Elwood said: “This is not like a guy accused of murdering his loving wife. This is a guy who thinks this is all a big joke.”

But Miralle said his grief over his wife’s death had been overshadowed by his anger at the judicial system. “If I can get over my anger for a while, maybe I can mourn for my wife,” he said.