SAN DIEGO (CN) – The man accused of killing homeless San Diegans in a 2016 murder spree appeared in San Diego Superior Court Monday for a competency trial that will also determine whether he can assist in the defense of his case.
Jon David Guerrero faces murder, attempted premeditated murder and arson charges for allegedly attacking several people, and he could face the death penalty if convicted. The victims – primarily homeless men who were alone and sleeping late at night – were stabbed and set on fire. Four people were killed in the crime spree.
Authorities believe the first attack occurred in February 2016. Several attacks occurred over the July Fourth weekend that year.
Police arrested Guerrero on July 15, 2016 after responding to reports of another attack that night. He was found in the area of the crime, carrying a backpack filled with railroad spikes and a metal-headed mallet. He pleaded not guilty to four murders in April 2017 after his competency was restored.
The competency finding was short-lived, however, and since his arrest Guerrero has been held at the Patton State Hospital in San Bernardino County. His competency trial has been rescheduled several times.
On the first day of his competency trial Monday, brain imaging specialist Dr. Jeffrey Lewine told the court that Guerrero’s brain has abnormalities that would hinder his ability to participate in a trial. Lewine analyzed MRI brain scan images and reviewed other testing conducted on Guerrero in the last nine months.
Lewine said he is particularly concerned about Guerrero’s ability to understand information and his executive functioning – higher cognitive functions including communication, behavioral skills and memory.
“Mr. Guerrero is a complicated case,” Lewine said. “From a neuroimaging perspective, it is clearly an abnormal brain.”
Lewine said the behaviors associated with Guerrero’s brain abnormalities are “not something he could fake” and likely stem from a combination of schizophrenia, substance abuse and minor traumatic brain injuries Guerrero sustained in his youth.
Guerrero is “reasonably well-medicated,” Lewine said, and he has been housed for more than a year in a stable hospital environment where he has a routine. However, the expert said that Guerrero’s cognitive functions are likely to diminish if he is held in jail while appearing in a “stressful” trial.
“This is the best we will ever see from Jon,” Lewine said.
Judge Kenneth So asked Lewine if the test results show the extent of Guerrero’s cognitive impairment.
“Not in isolation,” Lewine said, adding that the brain scans must be considered alongside psychological analyses.
When pressed by Deputy District Attorney Makenzie Harvey as to whether Guerrero had ever responded illogically when he was treated by physicians, Lewine said he had not and that the defendant can process information when he is given “sufficient time” to do so.
“If you have problems in decision-making, in processing information, you’re not able to follow critical information being presented in a courtroom,” Lewine said.
The competency trial is expected to last more than a week.
Deputy Public Defender Dan Tandon is representing Guerrero.