A forensic scientist testified Tuesday at Robert Blake's (search) murder trial that the former "Baretta" (search) star had far less gunshot residue on his hands than would have been expected if he had shot his wife.

Celia Hartnett, who has worked in the field for 32 years, was hired by Blake's defense to reanalyze results presented by the prosecution earlier in the trial.

She said she conducted a test firing of the weapon with ammunition from the same manufacturer and with the same specifications as the bullet that killed Blake's wife, Bonny Lee Bakley (search).

She said she found that when two shots were test-fired in rapid succession, the gun produced 2,440 particles of gunshot residue. Calculations showed that after 2 1/2 hours, the length of time that elapsed before Blake's hands were tested by police, he would have been expected to have 97 or 98 particles on his hands, she said.

But she said the samples submitted to her from Blake's hands showed only four particles.

Bakley, 44, was shot to death in 2001 as she sat in a car near a restaurant where they had dined. Blake contends he returned to the car to find Bakley mortally wounded after leaving her briefly to return to the restaurant to retrieve a handgun he claims he carried for protection.

Hartnett, laboratory director of Forensic Analytical in Heyward, said she took into consideration that Blake handled several objects, including glasses of water, and rubbed his hands on his hair, on the grass and on his clothes before he was tested.

A prosecution expert found five particles were present on Blake's hands rather than four. Hartnett explained that she isolated lead-only particles, while the prosecution expert counted one that contained phosphorous.

"Does the presence of gunshot residue on someone's hands necessarily mean that person has recently fired a gun?" asked Blake's lawyer, M. Gerald Schwartzbach.

"No, they do not," she said, noting that if the person touched any item containing gunshot residue, he would have it on his hands.

She said this could include touching Bakley's body or the car in which she was shot.

Prosecutor Shellie Samuels attacked the witness's testimony, suggesting that Hartnett's lab did not use the same ammunition that was used in the Walther P-38 gun that killed Bakley.

Hartnett said that the ammunition was difficult to obtain because it had gone out of production in 1994, but she said the ammo tested had the same powder, bullet style and powder load.

The issue of gunshot residue has dominated the trial. Several witnesses have said that Blake's hands should not have been tested at all because he was carrying a gun the night of the killing — a gun other than the one that killed Bakley — and that could account for the particles.

Later Tuesday, a San Bernardino County sheriff's deputy was called by the defense in an attempt to undermine the credibility of one of the state's star witnesses.

Stan Ware said he and other deputies were called to the home of retired stuntman Ronald "Duffy" Hambleton on Dec. 26, 1999, because of "armed men in his house and he was holding them off at gunpoint." When they responded, they found only Hambleton, who was waving a gun at the deputies, Ware testified.

Hambleton has testified that Blake solicited him to kill Bakley. Several other defense witnesses have painted Hambleton as a hallucinatory abuser of methamphetamines.

Schwartzbach planned to rest his case Wednesday. The list of final witnesses did not include Blake. But his oldest daughter, Delinah, is scheduled to be one of the final witnesses.