TAMPA — Devon Arthurs, the one-time neo-Nazi accused in the murders of his two roommates at their New Tampa townhouse, has autism and schizophrenia among other conditions, several mental health experts testified Thursday.

But the doctors who have examined him differed in their opinions about whether Arthurs can face trial.

Two experts who examined him earlier this year said he is competent to proceed in court. Three others, whose exams occurred more recently, said he is not.

A judge will have to decide who is correct. If Arthurs is deemed incompetent, he could return to the Florida State Hospital, where he already spent a year undergoing mental health treatment.

Arthurs, 20, was not present for the hearing, which lasted more than three hours.

On the witness stand in a Tampa courtroom, two defense experts described his condition in detail.

Related: Suspect in neo-Nazi murders tells of anger problem, says ‘I might be kind of sick’

Psychiatrist Michael Maher testified that he has examined Arthurs four separate times, including three exams this year. He has consistently deemed him to be incompetent to face trial.

Maher gave Arthurs a primary diagnosis of schizoaffective disorder, with underlying symptoms of schizophrenia, bipolar disorder and autism.

When asked open-ended questions, Maher noted, Arthurs quickly got distracted, his speech becoming unintelligible. He experienced auditory hallucinations — voices that criticize and accuse him. He believes he can communicate with his dead roommates and that he can feel and smell things related to the shootings.

The doctor also noted an alarming pattern of habitual self-injury. Every few minutes during the doctor’s visits, Arthurs would wrap his hands around his own neck and squeeze until his head dropped into his hands and he began to lose consciousness. The behavior was so frequent that Arthurs had what the doctor described as stretch marks on his skin.

The doctor characterized the behavior as involuntary and compulsive.

Since he was sent to the Florida State Hospital, Arthurs has been heavily medicated with antipsychotic drugs.

He understands that bad things could happen to him in the judicial system, but believes it would be the result of “powerful background forces,” Maher said. He has a limited ability to communicate rationally with his attorneys.

Related: Suspect in shooting death of two north Tampa roommates returns from state mental hospital

Yolanda Leon, a neuropsychologist, opined that Arthurs has schizophrenia, but that autism is what makes him incompetent.

Arthurs professed a recent conversion to Christianity. But Leon said his knowledge of the faith is minimal. When asked about specific Bible stories, he seemed to have a poor understanding of them. At the time of the crime, Arthurs professed adherence to Islam, but seemed to have a shallow understanding of that faith. Before that, he was affiliated with a small group of neo-Nazis known as the Atomwaffen Division.

Leon opined that Arthurs remains incompetent and is incapable of being restored to competency. If that’s correct, it means there is no way Arthurs could be made well enough to face a criminal trial.

Leon described his condition as akin to having a severe intellectual disability: There is no way to change it. She said the best course would be for Arthurs to be placed in a mental health facility.

Arthurs is charged with two counts of first-degree murder in the May 19, 2017, shootings of Jeremy Himmelman, 22, and Andrew Oneschuk, 18. He also faces kidnapping charges, accused of holding several people at gunpoint after the killings in a nearby smoke shop.

Witnesses said Arthurs rambled about Islam before Tampa police arrived and convinced him to surrender. After his arrest, he told police his roommates were dead in their townhouse.

In an interrogation, he told detectives he shot the pair because they were neo-Nazis and they had ridiculed his conversion to Islam. The families of the victims denied they harbored such beliefs.

Related: Neo-Nazi Florida National Guard soldier gets five years in prison on bomb-making charges

As police processed the crime scene, they discovered a stash of bomb-making materials in an attached garage. The explosives belonged to a fourth roommate, Brandon Russell, who was said to be the leader of the Atomwaffen Division group. Russell later pleaded guilty to federal charges and is serving a five-year prison sentence.

Hillsborough Circuit Judge Laura Ward made no decision about Arthurs’ competency Thursday. A continuation of the hearing was scheduled for January.