Nhan Lap Tran, an Oakdale man accused of shooting and killing a 9-year-old boy in 2013, is incompetent to stand trial and will spend another six months in the state mental hospital because he’s not rational enough to consult with his attorneys, a judge ruled this week.

Washington County District Judge Gary Schurrer wrote in his order that “determinations by all of the doctors who have encountered Defendant are fairly consistent in finding that Defendant suffers from a major mental illness related to paranoid schizophrenia which affects his functioning to a great degree.”

Tran, now 36, faces several counts of second-degree murder for randomly shooting at passing cars on a cold night in February 2013.

He stood on Hadley Avenue near Seventh Street, about a block from his home in Oakdale, when he allegedly shot and killed 9-year-old Devin Aryal, a fourth-grader, who was seated behind his mother as she drove the family van. Another woman, driving with her three grandchildren, was injured when her vehicle was sprayed with bullets. Two other motorists narrowly avoided being shot in the 20-minute spree that started just after darkness fell.

Since his arrest that night, Tran mostly has been held at St. Peter Regional Treatment Center. He has appeared in court in Stillwater at least three times to determine whether he was capable of standing trial. Psychologist John Cronin, in a December 2014 report, described Tran as “delusional, unstable and extremely paranoid.”

Schurrer, in his order this week, wrote that he found no evidence that Tran “is malingering in an attempt to delay this matter.”

The court again will review Tran’s mental competency in six months, Schurrer wrote.

Tran’s parents, immigrants from Vietnam, said earlier they knew he needed mental health counseling but they couldn’t afford to pay for it.