BANGOR — An emotional David Coon pleaded guilty Thursday at the Penobscot Judicial Center to manslaughter in the May asphyxiation death of his girlfriend, Sherry Clifford, but the judge declined to accept his plea and continued the hearing after Coon denied touching Clifford’s throat.

Dr. Mark Flomenbaum, deputy chief medical examiner, determined that Clifford’s death was “caused by asphyxiation with some neck compression,” according to the affidavit filed when Coon was arrested.

“Flomenbaum discovered hemorrhaging in the neck region just under the jaw bone,” it said. “There was also hemorrhaging around Clifford’s hyoid bone.”

The hyoid bone is the U-shaped bone at the base of the tongue.

Police on May 3 found Clifford, 49, dead on the floor of the Jefferson Street apartment the couple shared in Bangor after Coon called 911 to report that “she OD’d or she drank herself to the death,” the affidavit said.

Coon told police May 3 that Clifford had “freaked out” and attacked him. He admitted that he “pinned Clifford to the floor and she told him that she could not breathe,” the affidavit said. “Coon stated that Clifford died while pinned to the floor. Coon said that he had covered Clifford’s mouth with his hand to quiet her.”

Clifford was a native of Bangor and owned a hair salon in the area for at least eight years.

Coon, 50, told Superior Court Justice Ann Murray on Thursday that he “did not touch her neck whatsoever.”

Defense attorney Jeffrey Silverstein of Bangor told the judge that his client does not remember all that happened the night Clifford died but did tell police he covered her mouth with his hands. He also told police his hands might have slid to her neck, according to court documents.

Coon was overcome with emotion several times during the hearing Thursday. Murray halted the proceeding at least twice so he could regain his composure.

“I haven’t felt right since May 3,” he said. “This was never supposed to happen.”

Assistant Attorney General Andrew Benson, who is prosecuting the case, said earlier this week that his office has a plea agreement with Coon. Benson said he would recommend Coon be sentenced to 25 years in prison with all but 12 years suspended, followed by four years of probation. Silverstein and co-counsel Logan Perkins would be free to argue for less time at sentencing, when the murder charge would be dismissed.

Murray recessed the hearing without accepting his guilty plea. She did not set a date to resume the proceeding but said it might not be until February.

Coon could enter a so-called Alford plea. An Alford plea, named for the U.S. Supreme Court case North Carolina vs. Alford and decided in 1970, is “a guilty plea that a defendant enters as part of a plea bargain, without actually admitting guilt,” according to Black’s Law Dictionary.

Coon has been held without bail since his arrest May 6.

The sentence for a murder conviction is between 25 years and life in prison. The maximum sentence for manslaughter is 30 years.