AUGUSTA (AP) – A psychiatrist says a 22-year-old man on trial for two counts of murder thought he was “doing the world a favor” by killing his former girlfriend because he believed she was part of an evil group trying to take over his mind.

Dr. Carlyle Voss took the stand for a second day Tuesday in the trial of John A. Okie. He’s charged with killing Alexandra “Aleigh” Mills, 19, in Wayne on July 10, 2007, and then his father, John S. Okie, six days later in Newcastle.

Okie’s lawyer, who’s using an insanity defense, is seeking to show that his client was mentally ill and incapable of understanding what he was doing at the time of the killings.

Voss, who was hired by the defense, testified Monday that Okie thought Mills was part of an evil group. “He believed he was actually doing the world a favor by killing her,” the psychiatrist said.

Okie didn’t appear to be interested in Monday’s proceedings in Kennebec County Superior Court. At one point, he closed his eyes and appeared to be asleep.

Voss explained under cross-examination Tuesday the basis for his finding that Okie was severely mentally ill at the time of the slayings and how his actions fit the symptoms of paranoid schizophrenia.

The psychiatrist quoted Okie as saying he believed he was doing good in killing Mills, a former classmate at Kents Hill School.

“I thought I did the right thing,” Voss reported Okie telling him in October. “He had no remorse at the time (of the killing),” Voss added. “Now he believes he was tricked by Cubans.”

Okie believed that killing Mills would prevent others from reading his mind, Voss said, but when he still felt his mind was open to all, he decided to kill his father.

Assistant Attorney General Andrew Benson said tests by a psychologist with the State Forensic Service showed a 97.9 percent likelihood that Okie was feigning symptoms to avoid taking responsibility for the murders.

The defense resumes Wednesday and the trial is expected to go to the jury later in the week.