AUGUSTA — A former patient at Riverview Psychiatric Center will likely spend the better part of the next decade in prison for attacking a pregnant mental health worker last year.

Mark Murphy, 48, was sentenced Monday in Kennebec County Superior Court to 15 years in prison with all but 10 years suspended and two years probation. Justice Donald Marden, who in January found Murphy guilty of aggravated assault and two counts of elevated aggravated assault following a one-day non-jury trial, said Murphy’s history of mental illness did not lessen his responsibility for the attack.

Marden, in delivering his verdict, agreed with the prosecutor’s contention that Murphy acted in anger rather than psychosis when he repeatedly punched and stabbed 26-year-old Jamie Hill-Spotswood, who was 18 weeks pregnant.

Murphy’s probation, which will begin when he is released from prison and likely returned to Riverview to continue treatment for his original offense, will require that he follow the rules of the facility or risk being sent back to prison. On Feb. 1, 2006, Murphy was found not guilty by reason of mental disease or defect in a break-in at a neighbor’s home in York County in November 2004. In that incident, the homeowner shot Murphy in the chest.

Court records also show the hospital reported that Murphy assaulted another patient with a fork on Oct. 9, 2007.

On Monday, Marden said Murphy lacks control.

“It’s difficult for the court to find mitigating circumstances because of mental illness,” Marden said during the sentencing hearing. “He just doesn’t have control or inhibition when he wishes to lash out.”

Marden said Murphy’s history suggests he would continue to be a danger if he went back to Riverview. The same history, and Murphy’s own testimony, indicates that he has “done well” in prison. Marden suggested the sentence was imperfect, but took into account a state system that is ill-equipped to treat Murphy while preserving the safety of other patients and staff.

“This is a difficult thing when the court is satisfied that some of Mr. Murphy’s actions are not of his own free will,” Marden said. “The court recognizes he is a very troubled person.”

Witnesses testified at the October trial that Murphy apologized to Hill-Spotswood immediately before attacking her and afterward flashed the middle finger at other hospital staff members who checked on him after he was sedated. Murphy was later sent to the Maine State Prison.

Hill-Spotswood testified at the trial that she screamed for help that day as Murphy beat her.