SANTA MONICA, Calif. (AP) _ O.J. Simpson's photo expert was attacked in court Friday as a conspiracy nut and high school dropout who's unqualified to analyze, much less brand as fake, a photo of Simpson in Italian shoes.

In the most contentious cross-examination of Simpson's wrongful death trial, a plaintiff lawyer portrayed Robert Groden as a Kennedy conspiracy buff with a desire to capitalize on the Simpson case.

Simpson's lawyer countered by accusing the plaintiffs of ``character assassination.''

Simpson, who initially was scheduled to testify Friday before jurors took off for a two-week holiday break, was not in court as he awaited a decision in his battle over custody of his two young children.

Sydney, 11, and Justin, 8, went to stay with their grandparents when Simpson was arrested in 1994 and charged with murdering their mother and Ronald Goldman. They were seeking permanent guardianship.

Friday evening, Orange County Superior Court Judge Nancy Wieben Stock awarded custody to Simpson, saying that his former in-laws, Louis and Juditha Brown, had failed to provide ``clear and convincing evidence'' that custody by Simpson ``would be clearly detrimental to their well-being.''

The families of Ms. Simpson and Goldman filed the wrongful death lawsuit against Simpson last year after he was acquitted in their slayings.

The photo which Groden analyzed for the defense was the only powerful new piece of evidence to surface after Simpson was acquitted of the killings. It shows Simpson wearing the same style of Bruno Magli shoes as the killer.

Simpson has insisted from the outset that the picture is a fake.

The plaintiffs tried to keep Groden off the stand, claiming he was unqualified as an expert, but Superior Court Judge Hiroshi Fujisaki allowed him to testify and suggested ``vigorous cross-examination'' could be used to challenge him.

Groden, who branded a powerful evidence photo of Simpson a fake, remained unruffled during the verbal attack.

He admitted he'd done some questionable things _ like selling John F. Kennedy autopsy information to a supermarket tabloid and taking part in a JFK motorcade attraction in Dallas that included a tape recording of gunshots as tourists drove along the assassination route.

He said his ``life's work'' is studying the JFK assassination and he has written five books promoting a conspiracy theory.

Plaintiffs attorney Peter Gelblum also managed to establish that Groden was a high school dropout with no formal training in photography, and that he was discharged from the Army after only one year's service, purportedly because he couldn't adjust to military life.

Groden said he has suffered strokes which affected his memory and he is being sued for allegedly using video footage of the assassination without permission in a video he was selling on the street.

When Gelblum suggested Groden stole government photos of the assassination, defense attorney Dan Leonard exploded.

``This is character assassination, your honor. It has nothing to do with the photographs in this case,'' Leonard protested. ``Ask some questions about the photographs!''

Fujisaki, clearly annoyed by the angry exchanges, summoned lawyers to his bench, then admonished jurors to disregard Gelblum's comments about theft.

``This is a case in which counsel cannot establish evidence by innuendo,'' he told jurors.

When Gelblum moved beyond the expert's credentials and tried to show jurors the picture was authentic, the results were muddled. Some of the features he pointed out were not easily visible on a large TV screen and an effort to demonstrate the size of the disputed frame of film fell apart when the compass being used for measurement proved inexact.

``This is ridiculous,'' the judge muttered.

Groden said the difference in size was perhaps one 10,000th of an inch and could not be seen unless it was blown up by 400 percent.

Pressed to change his opinion of the photo, he said, ``To my satisfaction, I'm sure it's a fake.''

Fredric Rieders, founder of National Medical Services laboratory in Willow Grove, Pa., was the last defense witness called before the holiday vacation.

He testified that EDTA, a chemical used by laboratories to preserve blood samples, was detected on blood samples from a sock found in Simpson's bedroom and the back gate at Ms. Simpson's condo.

The suggestion is that the blood came from a laboratory tube containing Simpson's own blood and was planted.