By MICHAEL G. MOONEY
BEE STAFF WRITER
(Published: Thursday, November 18, 1999)

   The testimony of an expert witness and two former neighbors of Douglas Mouser questioned Wednesday whether Mouser murdered his 14-year-old stepdaughter Genna Lyn Gamble in October 1995.

   Mouser is accused of strangling the Beyer High School freshman and then dumping her nude body in a remote agricultural area near Waterford.

   Early in his testimony Wednesday in Stanislaus County Superior Court, James R. Williamson, who holds a doctorate in civil engineering and specializes in photogrammetry, challenged the work of Canadian photogrammetrist Gary Robertson, who testified for the prosecution.

   Photogrammetry has been used for years in aerial surveying, as well as the investigation of car and plane crashes. Robertson, through the use of digital technology, computers and specialized software he developed, has adapted photogrammetry for use in criminal investigations.

   After analyzing photographs provided by the prosecution, including autopsy pictures, Robertson concluded marks and indentations on Gamble's right leg were caused by the bare skin coming into contact with the edge of the back-seat carpet in Mouser's car. Robertson also found another mark he said was caused by a seat-belt buckle.

   Other prosecution witnesses said the marks were made after the girl was dead.

   Defense attorney Richard Herman has attacked Robertson's conclusions, saying his process was flawed.

   Williamson said Robertson didn't go far enough in his analysis, noting Robertson ignored a number of other marks found on Gamble's leg and body. Williamson, a veteran of the Central Intelligence Agency, once taught FBI agents how to analyze still and video pictures of robberies captured on cameras mounted in banks and convenience stores.

   "If you don't examine all that's there," he said, "you don't know if it relates to what you're working on."

   That comment and a host of others, drew immediate and repeated objections from co-prosecutor Birgit Fladager. Fladager said Williamson had never applied photogrammetry techniques to the human body. Judge Donald E. Shaver ruled in her favor on many of the objections.

   Herman, however, was able to ask questions that allowed him to get Williamson's main point before the jury -- that Robertson had erred in his analysis.

   Mouser acquaintances Barbara Arnold and Gilbert Yacoub also testified.

   Arnold admitted under cross-examination by co-prosecutor Joseph "Rick" Distaso that she would do or say anything -- within the law -- to help the Mousers. She said she remains a good friend of the couple. Among other things, Arnold said Douglas and Kathy Mouser were good parents to both Genna and her brother, Gerren, and never would have hurt either child.

   Distaso asked her a number of questions about the condition of the garage at the Mousers' Modesto home. Prosecutors believe Douglas Mouser pulled his car into the garage after killing the girl early in the afternoon so he could load her body without arousing any suspicion.

   The defense claims the garage was bloated with items for a planned yard sale, leaving no room for either Mouser's Honda or his wife's Ford Aerostar van.

   Arnold stuck to her story that the garage could not have held a car on the day Gamble died, despite statements attributed to the Mousers that Kathy had pulled the van into the garage. If Kathy Mouser made that statement, Arnold insisted, she must have been confused about the day.

   Yacoub testified he saw a girl who resembled Gamble walking from the direction of the Mouser house between 11 a.m. and noon that day, although it probably was closer to 11 a.m.

   Other witnesses have testified they were talking on the telephone with Gamble between 11 a.m. and 11:15 a.m.