Contradicting testimony by a pair of defense experts, a neurologist on Tuesday testified that there is no evidence to suggest that Thousand Oaks convicted murderer Mark Scott Thornton suffers from a brain dysfunction.
Dr. William W. Sutherling, medical director of the Epilepsy and Brain Mapping Program in Los Angeles, disputed the results of a brain-wave test in which the 20-year-old death-penalty defendant was diagnosed as having a mental deficiency.
Thornton was under the influence of anti-psychotic medication and was drowsy when he underwent the electroencephalogram test--factors that likely decreased his brain-wave pattern and adversely affected the exam results, the doctor testified.
Thornton was found guilty in December of first-degree murder for the shooting death of Westlake nurse Kellie O'Sullivan. She was shot three times in the Santa Monica Mountains after being kidnaped in Thousand Oaks on Sept. 14, 1993.
Testifying before the Ventura County Superior Court jury deciding whether Thornton should be executed or sentenced to life in prison, two defense experts have diagnosed the defendant as having brain damage. The defense contends the brain damage affected his ability to think before shooting the nurse.
Sutherling strongly disagreed with his colleagues, saying he fully expects Thornton would score on par with most young men his age if given the test again at a time when he is not medicated.
Defense attorneys conceded that Thornton had taken medication 24 hours before being tested.
The trial, expected to last at least another week, continues with more prosecution testimony today.