By MICHAEL G. MOONEY
BEE STAFF WRITER
(Published: Thursday, November 11, 1999)

   The defense belief that Genna Lyn Gamble was killed near the remote creek bed where her body was discovered more than four years ago rests -- in no small part -- on the observations of one John L. Thornton.

   Gamble's stepfather, Douglas Mouser, is accused of strangling the Beyer High School freshman during an October 1995 family argument. The Modesto teen's nude body was found sprawled on a steep embankment above Dry Creek, just off Tim Bell Road near Waterford.

   Attorney Richard Herman began laying out the defense case last week in Stanislaus County Superior Court, after co- prosecutors Birgit Fladager and Joseph "Rick" Distaso rested. Thornton, who took the witness stand Tuesday and concluded his testimony Wednesday, is a critical witness for the defense.

   Thornton, professor emeritus of forensic science at the University of California at Berkeley and a national expert in crime scene reconstruction, dipped into the same palette but ended up with a picture far different from the one painted by the prosecution.

   During his testimony Thornton said:

   * Gamble's body was carried up the steep embankment -- by two people -- to the spot where it was discovered, rather than rolled down as theorized by Sheriff's Department investigators.

   * Scratch marks left on the girl's torso indicate that her body was held under her arms and by her feet. As she was carried up the steep slope, her torso dragged along the ground, leaving linear scratch marks on her abdomen and chest. The marks were not consistent with a body's tumbling down a hillside.

   * Photographs taken at the crime scene show a path beaten through the weeds extending from the creek to the body, further suggesting that she was dragged from the bottom rather than rolled from the top of the embankment.

   * No blood smear was found on Gamble's upper lip or elsewhere on her face. Had she been rolled down the hill, blood would have seeped from her nostrils. Other pictures show the blood did smear on her upper lip after investigators carried her body to the top of the embankment.

   * There were no fibers on the body. Sheriff's investigators believe an impression found on Gamble's leg was made after she died. They say the body was put in a car, and the mark came from the edge of the car's carpet. Although fibers from the carpet were located throughout the car, not one was found on Gamble's body.

   Herman, in a series of questions at the outset of Thornton's testimony, stressed the professor's credentials, which include an armful of degrees, special board certifications, awards, professional associations, published articles and contributions to textbooks.

   Herman noted that Thornton has been tapped as an expert witness by prosecutors, approximately 25 percent of the time, as well as defense attorneys. In addition, Thornton has been involved in some 800 murder investigations.

   Other witnesses who have testified on behalf of the defense in recent days included Isabelle Van Sicklen, a Modesto marriage and family counselor, and Daniel Cron, a retired forensic photographer who worked for the Sheriff's Department at the time of Gamble's death.

   Herman said Van Sicklen, in testimony Friday, told the jury she was counseling Gamble and her mother, Kathy Mouser, in the months before the girl was killed. He said Van Sicklen noted that Gamble's rebellion against parental authority, known as oppositional disorder, was directed exclusively against her mother.

   Kathy Mouser is expected to testify Friday, when the trial is scheduled to resume in the courtroom of Judge Donald E. Shaver. Courts are closed today in honor of Veterans Day.

   Staff writer Michael G. Mooney can be reached at 578-2384.