Was Peter Jordan Chiesa responsible for his own actions when he killed two women near his home in Wallace?
That´s the question defense attorney Clyde Blackmon left with jurors as they heard testimony Friday afternoon about brain damage Chiesa has suffered.
Dr. Daniel Amen, who operates several clinics, including one in Fairfield, presented the jury with images of Chiesa´s brain taken during a Single Photon Emission Computerized Tomography, or SPECT, scan.
Chiesa is charged with two counts of first-degree murder for the June 25, 2002, shooting deaths of Leslie Hannameyer, 43, and Annette Truman, 41.
The two women, neighbors of the Chiesas, were clearing limbs and other debris from a tree-trimming operation along a common driveway on an easement through the Chiesa property shared by the three families.
According to authorities and witnesses, Chiesa, armed with a rifle and handgun and believing the women were taking wood that belonged to him, approached the pair, shooting Hannameyer in the back of the head at close range, and killing Truman as she fled across the road.
Chiesa then went to his home where deputies spent three hours on the telephone with him before he surrendered.
Blackmon has not disputed Chiesa killed the women, but is asking the jury to consider the degree of the killings, whether they were first- or second-degree or manslaughter.
During Amen´s testimony Friday, the doctor compared images of Chiesa´s brain taken Sept. 22 and 23 with those of “healthy” brains, noting that blood flow to parts of Chiesa´s brain is greatly diminished, creating limited brain activity.
Those areas control behaviors such as judgment, impulse control, reading social cues, and temper control, Amen said.
A base number of “0” is used to describe the blood flow of a healthy brain. From there it can range from a high of 4, representing overstimulation, to 4-minus, where there is a lack of brain activity.
In Chiesa´s case, the activity ranged from 3-minus to 4-minus.
“It almost doesn´t get any worse than that,” Amen said.
He also said it would take a severe physical trauma to cause such problems.
Blackmon has previously stated his client, who otherwise was a brilliant man, awarded several patents in chemistry, suffered a stroke in 1993 and underwent bypass surgery in 1996 at which time he was on a heart-lung machine for about 2½ hours, suffering more brain damage.
Amen could not pinpoint just when Chiesa suffered the damage revealed in the scans, but did not believe it had occurred since the killings, saying such damage was a result of severe trauma.
Under questioning from Deputy District Attorney Seth Matthews, Amen said there are a number of treatments for Chiesa´s conditions, including medication, a change in diet or exercise, and alternative methods such as using powerful magnets to stimulate underused areas of the brain.
“So there´s lots of things that you can do,” Amen said.
Because of Amen´s schedule, his testimony interrupted a continued appearance by Chiesa´s wife, Donna, who testified Thursday.
She is expected to take the stand again when the trial resumes Wednesday.
Calaveras Enterprise story by Craig Koscho. For more Calaveras news, click: calaverasenterprise.com