BANGOR, Maine — The man charged with killing a Hudson contractor pleaded not guilty to murder Friday.

Peter Robinson, 48, of Bradford was indicted Wednesday for intentional or knowing murder and depraved indifference murder in the death of David P. Trask, 71.

Just prior to Robinson’s arraignment at the Penobscot Judicial Center, Superior Court Justice William Anderson continued a probable cause hearing held to determine whether the defendant had been properly charged. Robinson’s attorney, Thomas Hallett of Portland, told the judge there might be enough evidence to charge his client with manslaughter, but not with murder.

Assistant Attorney General Andrew Benson, who is prosecuting the case, said there was probable cause for a murder indictment by the Penobscot County grand jury. Benson also said Robinson should be denied bail.

The issue is important, according to Hallett, because bail is not allowed for defendants charged with murder but is allowed for those charged with manslaughter.

A decision about when the hearing will resume was not made Friday, both Hallett and Benson said as they left the courthouse. The lawyers agreed it most likely would be reconvened before Christmas.

The defense attorney conceded outside the courthouse that it would be highly unusual for a judge to find there was not probable cause for a murder charge after a grand jury had determined there was.

Maine State Police Detective Jay Pelletier and Deputy Medical Examiner Michael Ferenc testified during Friday’s hearing. Both answered questions about information contained in the affidavit in support of the warrant that led to Robinson’s arrest, but did not testify to much new information other than the fact that Trask had been diagnosed with rheumatoid arthritis.

Friends and family members of both Robinson and Trask filled the large ceremonial courtroom on the second floor of the Penobscot Judicial Center.

Members of the Trask family declined to speak to the media after the hearing. Hallett spoke on behalf of Robinson.

Hallett’s self-defense argument is based, in part, on information in the affidavit. It was made public Thursday and described a history of disputes between Robinson and Trask over alleged trespassing and a right-of-way issue.

Robinson called 911 about 2 p.m. Nov. 12 to report Trask’s death.

“He came at me with a crowbar, I took it out of his hands and I struck him in the head a couple of times and I think he’s dead,’’ Robinson told a dispatcher at the Maine State Police barracks in Orono, according to the affidavit. “We had a confrontation, he came at me with a crowbar, I took it out of his hands and I clubbed him with it.”

Trask died of head injuries with extensive fractures, Ferenc testified Friday. Trask suffered at least three impacts consistent with a broad, heavy object hitting his chest and face. The first blow was to the chest and caused multiple rib fractures.

Another blow was to the chin and broke Trask’s jaw, Ferenc said. The dead man’s false teeth were found broken on the ground near his body.

The fatal blow “caved in his face” and injured the brain, the medical examiner testified. Ferenc said it was his opinion that Trask was on the ground, on his back, when he was struck in the face.

The medical examiner also testified that he found no defensive wounds on Trask’s body.

The affidavit described several previous encounters between Robinson and Trask and-or his relatives.

In February 2009, a Maine warden issued trespass warnings to Trask and five male relatives after Robinson complained they were hunting on his posted land, according to the affidavit. Robinson allegedly told the warden the next day, “If I ever catch them down in there again, I’ll probably kill them,” the affidavit said.

Earlier this year, Trask purchased a lot with a right-of-way on Robinson’s land. Cheryl Robinson, the defendant’s wife, allegedly told police who came to investigate Trask’s death that her husband had intended to confront Trask about an unlocked gate at the entrance to Bear Road.

Although Robinson called the purported murder weapon a “crowbar,” Pelletier described it as a “pinch bar,” weighing about 15 pounds and 56 inches long. It has a pointed, projecting end and is used to roll heavy objects, according to Webster’s New World College Dictionary, 4th edition.