BANGOR, Maine — The LaGrange man charged last year with murdering his naked wife while she was hiding under the couple’s bed pleaded guilty to manslaughter on Wednesday morning in Penobscot County Superior Court.

Jeremy Hart, 35, is not expected to be sentenced next month for shooting his wife, Kristen Smart Hart, who was 25 at the time of her death on Nov. 29. She died of a gunshot wound to the head during a party where guests said that cocaine was used.

Under the terms of his plea agreement, Assistant Attorney General Andrew Benson will recommend Hart serve 15 years in prison. Defense attorney Stephen Smith of Bangor is expected to argue for a lesser sentence and most likely will ask that a portion of it be suspended.

Hart will serve at least four years. That is the mandatory minimum prison term for a manslaughter conviction that involves a gun.

The murder charge is expected to be dismissed after he is sentenced.

Half a dozen female relatives and friends of the victim attended the 45-minute hearing.

Kristen Hart’s younger sister, Vanessa Smart, 25, of LaGrange, said outside the courtroom that the family was not happy that her brother-in-law was allowed to plead to the lesser charge.

“I believe it was murder and completely intentional,” she said. “He planned it. She wasn’t doing anything he didn’t already know about.”

Smart also said that 15 years in prison was too short a sentence.

“He should serve more time,” she said.

Hart remains free on $100,000 cash bail posted in June by his father, Ron Hart, of California.

Benson argued Wednesday that Hart should be held without bail until his sentencing because he had talked his wife’s cousin into digging up her ashes for him. The prosecutor also said that Hart had been using drugs but Benson did not file a motion to revoke his bail.

Smith said that his client was ready to submit to a drug test as soon as the hearing was over. But Hart was not required Wednesday to submit to a drug test.

The defense attorney told the judge that Hart had denied digging up his wife’s ashes. Smith declined to discuss whether Hart had asked someone else to obtain his wife’s ashes.

After Wednesday’s hearing, the victim’s family members declined to say what has happened to Kristen Hart’s ashes.

Hart was in the Penobscot County Jail when his wife’s memorial service was held on Dec. 5 at the Masonic Hall in LaGrange.

Superior Court Justice William Anderson amended Hart’s bail condition Wednesday to prohibit him from using illegal drugs or alcohol. Hart also is now subject to random search and testing to see if he is in compliance. Conditions set in January included no possession of weapons and no contact with witnesses or his three children.

Hart has not seen his two daughters and son since his arrest. The older girl, now 10, is living in northern California with Hart’s mother, according to Smith. The younger girl, now 7, and boy, now 3 are living with their paternal grandfather in southern California. Hart’s parents are divorced.

Vanessa Smart said after Wednesday’s hearing that she and other family members were concerned for their safety while her brother-in-law remains free.

“We’re very concerned for our safety,” she said. “We do not think justice is being served.”

In an interview with police a few days after his wife’s death, Hart admitted that he picked up his rifle that was in the couple’s darkened bedroom after he found a man sitting on his bed during the party.

A 25-year-old male party guest told investigators that he was in the bedroom “kissing” and “fondling” Kristen Hart when her husband entered the darkened bedroom. The man said that he “saw Jeremy fire two shots from a rifle out a window and that [he, the witness] went to the floor; that [he] heard more shots fired while he was on the floor,” according to court documents.

Detectives arrested Hart on Dec. 2 after they traced the trajectory of five bullets in the couple’s bedroom. The angles converged in the area toward the foot of the bed where Hart believed his wife to be, according to court documents.

Smith said Wednesday that Kristen Hart popped her head out from under the bed just after her husband pulled the trigger the last time.

“This was a really tragic accident,” Smith said late Wednesday afternoon. “These folks lived a lifestyle the average person wouldn’t understand. It’s fair to say that he certainly didn’t intend to kill his wife.”

Benson declined to comment on the manslaughter charge. It is the policy of the Attorney General’s office not to comment on cases until after they have been resolved.