CARIBOU – A Bangor psychologist told Aroostook County Superior Court Justice E. Allen Hunter on Thursday that Christopher Shumway is psychotic, suffering from severe post-traumatic stress disorder.

Dr. Ronald Brown testified that Shumway, who is on trial for murder in the Jan. 2, 2005, killing of Erin Sperrey at a Caribou doughnut shop, went into a PTSD “rage-reactive” state for a period of minutes and has no recollection of his actions during that time.

That is the period when Shumway is said to have beaten Sperrey to death in the walk-in cooler and employee restroom of the Tim Hortons restaurant. Brown testified that a comment by Sperrey about incestuous sexual abuse by his biological father, David Shumway, may have “triggered” the episode.

Brown’s testimony contradicted two state mental health professionals who testified Wednesday that Shumway was not psychotic when he killed Sperrey, his supervisor at the Bennett Drive doughnut shop.

Shumway’s jury-waived trial on charges of murder, gross sexual assault and robbery has been under way since Monday. He has pleaded not guilty and not criminally responsible by reason of insanity. The trial continues today.

Brown, who was on the witness stand all day Thursday, was questioned for several hours by Brad MacDonald, Shumway’s defense attorney from Bangor, and cross-examined extensively by Assistant Attorney General Andrew Benson.

“There was a sudden descent and loss of awareness when Erin Sperrey reminded Mr. Shumway of his father’s actions,” Brown testified. “He suffered a loss of control, his anger rose to a rage, and he was unaware of his actions.

“During this time of violent action, Mr. Shumway may not be aware of what he was doing,” Brown said at another point. “He believes he was the only one there [with Sperrey], so he must be the one who killed her.”

He said the episode when Sperrey was killed “may have been the most intense rage” Shumway had experienced in his life.

The entire incident, according to Brown, started when Shumway went to a walk-in cooler where Sperrey was getting bread. Shumway told Brown that Sperrey lashed out at him and told him to get back to the front of the store. It was then that she supposedly mentioned his sexual abuse.

Prosecution mental health professionals testified Wednesday that while Shumway suffers from several mental disorders, he was not psychotic at the time of Sperrey’s killing.

Psychosis is a major mental disorder in which the personality is seriously disorganized and contact with reality is usually impaired.

Brown testified that Shumway was not telling state examiners the truth when they interviewed him in the months after the crime. He said it was that way until Shumway was convinced by his attorney to be more forthcoming.

Shumway, Brown said, told state examiners a made-up story, the same one he told Maine State Police detectives the morning he was arrested in Bangor on Jan. 3, 2005.

Brown told the court that Shumway suffers from PTSD, severe depression, a substance abuse disorder, anti-social personality disorder, and psychotic disorder, not specified. He also was said to be a sexual deviant and had fantasized many times about having sex with Sperrey.

Shumway, according to the doctor, has blackouts and flashbacks of his father’s abuse.

The doctor told the court that Shumway’s abuse at the hands of his father started when he was 4 years old and lasted years. The youngster reportedly was told by his father that he would kill him and his mother if the boy ever told their “little secret.”

It is alleged that Shumway killed Sperrey, his supervisor, around 7 p.m. Jan. 2, 2005. He also is alleged to have molested her pre-mortem or at the time of death and to have stolen more than $1,200 from the store office before leaving in Sperrey’s car.

Witnesses have testified that Shumway was enamored of Sperrey, who spurned his advances, and that he had talked of stealing money to allow him to return to Massachusetts where he grew up.

The state claims Shumway beat Sperrey to death using his hands and feet, put her lifeless body in her own car and drove away from Caribou with her body and the money he stole. He drove from Caribou to Fort Fairfield and onto Interstate 95 at Houlton. While driving in a snowstorm, Shumway went off the road onto the highway median near mile 231. The car ended up lodged against a rock ledge.

Several witnesses said Shumway served them at the restaurant, both at the drive-through window and at the customer counter inside, while Sperrey lay dying in the employee restroom.

It is alleged further that at some point after leaving the restaurant he stopped the car, undressed the lifeless Sperrey and molested her.

Shumway was arrested at a Bangor motel some six hours after the disabled car with Sperrey’s body inside was found near Lincoln on Jan. 3, 2005. He has been held since at jails in Aroostook and Washington counties without bail.

Brown said he interviewed and tested Shumway over 25 hours during eight visits from January to June of this year. He said Shumway has tried to kill himself four times since Sperrey’s death, the last time while he was in jail in Machias.

He has been arrested several times over the years, as a juvenile and adult. He was on probation for sexual harassment by telephone at the time of his arrest for Sperrey’s killing.

Shumway has been treated many times for mental issues since he was 14 years old. He was hospitalized three times in Massachusetts institutions. He was medicated for his disorders, but had not been taking his medications at the time of the incident at Caribou.

He was said to seriously abuse alcohol and drugs, and had done so 24 hours before the killing at a New Year’s Eve party in Caribou.

Under cross-examination, Brown agreed with Benson that his diagnoses could change if it were shown that Shumway was telling the truth to state examiners and lying to him.

“I don’t believe I’m wrong,” he testified under cross-examination, “but it’s possible I may be wrong.”

He said the disagreement with the state examiners was a “difference of opinion.”