A Russian hacker at the center of a grueling 18-month extradition battle between Moscow and Washington over the theft of data on more than 100 million people has sparked another feud—this time between mental health specialists who can’t agree on whether he’s a troll or a victim.

Yevgeniy Nikulin’s defense team wants a judge to believe he may have been driven to the brink of psychosis by childhood abuse, compounded by hard time in a Czech prison watching Russia and the U.S. fight for the right to take him away. Prosecutors argue he’s a narcissist faking the symptoms of more serious mental illness in an attempt to hack the U.S. justice system.

Depending on which of these views is accepted by a federal judge, Nikulin might go home to Moscow or off to a federal prison.

Nikulin, 31, was picked up on vacation in Prague in 2016 on a U.S. indictment charging him with hacking into Dropbox, LinkedIn and Formspring and stealing data on 100 million people. He arrived in California last year after the U.S. fended off a competing extradition request by the Russian government that sought to get him back home.

When Nikulin stepped into a San Francisco courtroom in the spring of 2018 he looked as though he’d been stretched thin by the tug-of-war between the two countries. He was gaunt and hollow-cheeked, his narrow frame swimming in a jail uniform like a child playing dress-up. Since then, he’s shown few signs of interest during his court appearances, and the deputy marshals who take him to court have described him as “unresponsive,” hostile and violent.

At one point deputies brought him to a nearby hospital for medical clearance, and he repeatedly tried to walk away “and shoved the deputy when confronted,” the U.S. Marshal’s Service wrote to the court. On other occasions he vandalized holding cells and physically resisted his escorts during transport. Nikulin missed at least one court appearance entirely when he simply refused to leave his cell.

“ If the condition is incurable, then prosecutors have to drop charges and he’ll be sent back to Russia for treatment. ” — Arkady Bukh

His lawyers say he’s also refusing to cooperate in his defense, out of certainty that his attorneys are working against him with the government. Last year U.S. District Judge William Alsup ordered dueling psychiatric evaluations performed to determine Nikulin’s fitness for trial: one report by a government doctor, one by a doctor hired by the defense.

Now the results of those evaluations are in, and the two doctors have very different diagnoses.

The psychiatrist hired by Nikulin’s lawyers, Dr. Alexander Grinberg, diagnosed the hacker with possible post-traumatic chronic stress disorder, dissociative and conversion disorder, and psychotic disorder. The government’s expert, Bureau of Prisons forensic psychologist Dr. Lesli Johnson, concluded that Nikulin suffered from only one chronic mental health issue: narcissistic personality disorder.

“ He was staring pretty intensely at me, often smirking or widening his eyes, sitting forward, moving his head up and down almost to mock me ” — Dr. Lesli Johnson

On Wednesday, prosecutors filed a 19-page brief urging Alsup to reject Grinberg’s conclusions and accept Johnson’s. There’s a lot at stake for Nikulin, who potentially faces years in prison for his alleged hacks. If Nikulin is judged medically incapable of understanding the charges against him and participating in his defense, his date with an American jury would be postponed or canceled entirely.

“If the condition is curable, then they have to get him to a condition that will make him able to stand trial,” defense attorney Arkady Bukh told The Daily Beast. “If the condition is incurable, then prosecutors have to drop charges and he’ll be sent back to Russia for treatment.”

The government’s assessment of Nikulin involved lots of surveillance. Nikulin was transferred to a federal pre-trial detention center in Los Angeles and placed in the general population for eight weeks, during which Johnson sifted through translations of the emails and phone calls he made to his girlfriend from jail. “The evaluation really begins the day the defendant steps into our doors,” Johnson said at an April 29 hearing.

She also checked in regularly with the guards on his unit to find out how Nikulin was behaving, and how other inmates were reacting to him. “Other inmates tend to be pretty intolerant of people that they view as different, difficult or mentally ill,” she testified. “And at no point did any inmate come forward. And I assure you they come forward very quickly when they want somebody off their unit… Nor did officers ever observe any odd or bizarre behavior.”

Finally, she tested and interviewed him four times for a total of nine hours, during which Nikulin was usually staring at a picture on the office wall, “or he was staring pretty intensely at me, often smirking or widening his eyes, sitting forward, moving his head up and down almost to mock me,” Johnson testified. “That often seemed to happen when he did not agree with something that I said, when I challenged him in some way or when he thought that something that I asked was stupid, which was something that he referenced quite a bit.”

Based on a variety of factors Johnson concluded that Nikulin was faking some of his psychiatric indicators and concealing his real problem. “Narcissistic personality disorder specifically is a pattern—a pervasive pattern of a grandiose sense of self in need of admiration, and lack of empathy,” she testified. “These individuals often appear arrogant or have haughty behaviors… They often are interpersonally exploitative.”

Grinberg, the defense psychiatrist, didn’t have the benefit of placing his subject in a panopticon, but he speaks fluent Russian and was able to interview Nikulin without a translator. He also interviewed the lawyer who represented Nikulin in Prague, and Nikulin’s mother, who painted a stark picture of her son’s childhood, claiming he suffered violent abuse at the hands of his father.

The abuse began in-utero, she told the psychiatrist, with her husband frequently kicking and beating her during her pregnancy. When her son was three, her husband threw him violently to the floor. Nikulin didn’t speak until he was 6 years old, and she blamed his late development on brain trauma. In a later incident, Nikulin’s father brought home a machine gun and began firing it randomly inside the house, Grinberg reported.

Nikulin “might have been having significant lack of trust since his early childhood, when his father’s personality or behavior was changing dramatically between hugging him and then suddenly throwing him on the floor and expressing delusions that he's not his child,” Grinberg testified. “He could have very deeply rooted lack of trust in general.”

The Russian’s precarious mental state declined rapidly in 2016 after one of his two brothers committed suicide, Grinberg said, with Nikulin withdrawing into himself for a month. He was arrested in Prague later that year, and appeared to become delusional during his 18 months in the Czech jail, according to Grinberg’s report.

During a visit from his mother a few months after his arrest he complained in hushed tones that he was “exposed to radiation” in the jail. “I don't know what sensory input he got to come to this conclusion, so it could have represented some kind of hallucinations,” Grinberg testified. In a Jan. 1, 2018 phone call, Nikulin allegedly warned his mother not to return to Prague for another visit. “Don't come here, don’t come here, they will kill you by explosion.”

In its Wednesday filing, the government argues that Grinberg’s conclusions are based largely on assumptions drawn from anecdotes, and even if taken as true they don’t prove Nikulin is incapable of understanding the case against him or participating in his defense—the legal standard that matters. “Dr. Grinberg does not establish how delusions about radiation affect the defendant’s reasoning with regard to his case,” prosecutors wrote.

Bukh, the attorney, said the defense team is preparing a response. He said he’s now able to talk with his client about trivial matters like the conditions in jail or the quality of prison food, but Nikulin still won’t discuss his case, and shuts down completely if anyone asks him what happened in Prague. “Any issues related to Prague, it’s a situation when the client has immediately changed his mood and can’t talk about it because he goes blank,” he said. “The last thing I want is to get ready for trial without the assistance of the client.”