GREENLAND, N.H. - The hulking figure who authorities say opened fire from his home on a drug task force, killing the town’s police chief and wounding officers from four departments, was out on bail awaiting trial on charges of steroid possession and assault.

Officers had reason to believe that Cullen Mutrie could be armed and dangerous when they descended upon his home in this rural town outside Portsmouth Thursday evening to serve him with a search warrant.

That visit went fatally awry when Mutrie allegedly began shooting before police could get inside, striking four task force members, as well as the chief of Greenland’s small department, New Hampshire Attorney General Michael Delaney said.

Police Chief Michael Maloney, 48, was days from retirement when he was killed by a gunshot to the head.

In a press conference, the attorney general offered scant details on the firefight that erupted on normally sleepy Post Road, declining to answer questions about whether the task force members were wearing bulletproof vests or other protection, citing an ongoing investigation.

Delaney also did not explain why Maloney accompanied the specialized task force.

“The Attorney General’s Drug Task Force was executing a search warrant; several members were there,’’ Delaney said. “We warned the [Greenland police], and the police chief was involved in assisting with the execution of the warrant.’’

Delaney’s office did not return subsequent calls.

After the gunfire subsided, police negotiators made brief contact with Mutrie before a long stretch of quiet, prompting them to send a camera-equipped robot into Mutrie’s 1940s farmhouse early Friday. That led to the 2 a.m. discovery of Mutrie and a female companion, dead in what Delaney said was a murder-suicide or a double suicide; their autopsies will probably be conducted Saturday.

An aunt, Sheila Mutrie, said the family was deeply pained. “We’re so very, very sorry about what has happened, to the police and everyone else,’’ she said in a phone interview, adding that she had seen no signs of trouble with the nephew who often helped her negotiate stairs and use her wheelchair.

“He was very dear to me,’’ she said. “We couldn’t believe it when we heard.’’

Mutrie’s mother, Beverly, still lives in Hampton Falls, where she is well regarded for her civic involvement. She owns a copy store in neighboring Hampton that she ran with Mutrie’s father, Charles, who died two years ago at age 69. The father purchased the home where his son had lived since 2006.

Richard McDermott, chairman of the Hampton Falls Board of Selectmen, said Mutrie seemed deeply affected by his father’s death, though he could not fathom what led him to snap.

Beverly Mutrie, a tall woman with silver hair and youthful blue eyes, went to work Friday at the copy shop, which shares a wall with a Western outfitter on a busy road flanked by local businesses and national chains. Friends and customers trickled in, offering condolences and support.

In a brief interview, she said she wished she could go back and change things with her son. She had not considered closing the shop and sequestering herself, she said, but “to tell you the truth, I wish it would all go away.’’

Seven miles north, about 250 people, many in uniform, gathered on the lawn of Greenland’s Town Hall to memorialize Maloney under the setting sun.

Before a moment of silence, the Rev. Robert Fellows offered a prayer. “We ask that you be with all of those who take a risk to protect us every time they put on a uniform or drive an unmarked car,’’ Fellows said.

Mutrie, who stood 6 feet 3 inches, weighed 260 pounds, and was two weeks shy of his 30th birthday, was a former volunteer firefighter with a smattering of police encounters, including a 2006 arrest in Portsmouth for punching a bouncer in the head and a 2010 arrest after Greenland police responded to a call about a dispute at his home.

When officers arrived on July 24, 2010, Mutrie’s then-girlfriend said she wanted a restraining order issued and told them that Mutrie kept at least five guns stashed in his home, in his car, and on his body, including one in the storage chest of his living room coffee table, according to a report filed by officer Wayne M. Young.

Inside, Young reportedly lifted the table’s lid and found a cache of vials containing powders and liquid labeled with the names of anabolic steroids, along with a scale. Returning with a warrant, police found guns and ammunition and confiscated the substances, which the state crime lab later confirmed to be anabolic steroids. Mutrie agreed to turn his guns over to police, according to Young.

Mutrie was found guilty of assault at Portsmouth District Court and given a suspended sentence. He was also ordered to submit to an anger-management evaluation, comply with any prescribed treatment, and avoid contact with the woman.

He appealed to Rockingham Superior Court, contending that he grabbed his girlfriend only to stop her from keying his car, and alleging that “Officer Young threatened to kick [his] door down if he did not consent to a search of his home.’’

His appeal was slated for trial in June, while the drug case, for which Mutrie was out on $10,000 bail, was scheduled for trial in September.

Delaney would not say what police were looking for when the task force sought to search Mutrie’s home this week. The task force, one of four such regional teams under Delaney’s auspices, uses federal grants to train and employ local, county, and state officers, as well as investigators from the attorney general’s office.

On a quaint residential street set back from Interstate 95, neighbors snapped to attention when they heard an unfamiliar pop-pop-pop coming from 517 Post Road about 6 p.m.

“It sounded like my son banging on our dining-room window panes,’’ said Michael Gordon, a community college chemistry professor who lives across the street. Instead, Gordon entered an empty room and saw an unbelievable scene unfolding.

“It was just a flurry of bodies,’’ said Gordon, 35, who had kept his distance from a neighbor known for revving chainsaws and motorcycle engines at night.

“It took a few seconds to sink in, because it was so unreal,’’ Gordon said. “And then it finally hit me that this was a gunfight, and then it was time to hightail it out. We were just holed up in the basement the whole night.’’

Mutrie’s 2010 arrest appeared to coincide with his departure from the volunteer ranks of the Fire Department in Hampton Falls. Fire Chief Jay M. Lord issued a statement offering condolences and said Mutrie resigned from the department “after a few years of very limited participation.’’

On his own Facebook page, Mutrie continued to list the department while identifying himself as a member of the Winnacunnet High School class of 2000 and as a Northern Essex Community College student studying to become a paramedic. A college spokesman said Friday Mutrie did not graduate and has not been enrolled since fall 2010.

In his high school yearbook entry, opposite a photo of the broad-shouldered Mutrie in a checked button-down shirt, the young man listed graduating as his chief achievement and reminisced about parties and “runningfrom50,’’ or fleeing the police. But he also included a poignant note to his parents, writing, “Thanks for everything & I love you.’’

Two of four wounded officers were released from the hospital not long after the shooting. Two more remained hospitalized.

Police Chief Anthony F. Colarusso Jr. of Dover said Detective Gregory Turner, who was treated and released for a gunshot wound to the shoulder, is “an outstanding police officer.’’

Officers stood outside University of New Hampshire officer Eric Kulberg’s Hampton home, where he was recuperating, saying the family sought privacy.

Officer Scott Kukesh of Newmarket and Officer Jeremiah Murphy of Rochester remained hospitalized. Murphy’s family declined comment.

Kukesh was shot in the collarbone just above the bulletproof vest he was wearing, said family friend Ralph Atkins, citing Kukesh’s father-in-law.

Kukesh, he said, is a “dynamite, top-notch guy.’’

Travis Andersen, Martine Powers, and Jenna Russell of the Globe staff contributed to this report. Moskowitz can be reached at emoskowitz@globe.com; Cramer at mcramer@globe.com; Conti at kconti@globe.com.