The suspect in the brutal stabbing and dismembering of his girlfriend told investigators he was frustrated because she wouldn’t have sex with him, officials said Thursday.

Justin Fields, 38, is charged with murder and abuse of corpse in the slaying of 52-year-old Tammy Bailey.

Bailey was stabbed more than 100 times with a survival-type knife that had an eight-inch blade.

When law enforcement found her, said Blount County Sheriff Mark Moon, her head was near her feet and one of her limbs had been severed.

Moon recounted the ordeal as told to sheriff’s investigators by Fields.

On Friday, his birthday, he and Bailey had gone out to several places in the Springville area and then returned to Bailey’s house on Bailey Drive where the couple lived.

“He had a drink of brandy and then went into his bedroom and was playing guitar,’’ Moon said. “He decided he wanted to have sex, so he went into her room and propositioned her.”

“She refused him,’’ Moon said, “and, according to his statement, it frustrated him, and he stabbed her in the chest.”

Fields told investigators that he blacked out, went back to his room and went to sleep. When he woke up (Saturday morning), he said, he thought he was having a bad dream, and stabbed her more than 100 times.

“We’re pretty sure she was dead on the first blow,’’ Moon said of the Friday night wound. “When he went back in there the next day, she had not moved.”

Fields called his father and told him he had “done something horrible,” and wanted to commit suicide. The father then called Bailey’s family member, who was also a neighbor.

The family member went to the couple’s home, but Fields would not let her inside. “He tells her what’s inside is terrible and she doesn’t want to see it,’’ Moon said. “She calls 911.”

When the first deputy arrived on the scene, about 5:30 p.m., he encountered Fields who was sitting on the front step. Again, Fields tells the deputy he’s done something bad, and the evidence is inside the home.

The deputy who spoke with Fields got a bad feeling, so he told him he was going to handcuff him for the safety of both of them. Fields told him, “That’s Ok. You’re going to arrest me anyway.”

Once backup arrived, two deputies entered the home. After clearing the rest of the house, then opened the door to the bedroom where they found Bailey’s mutilated body.

Fields has no criminal history listed in court records, and Moon said they’ve never dealt with him previously.

The sheriff said he doesn’t know of any mental history with Fields, who was interviewed twice by investigators following Saturday’s discovery.

“He admitted to my investigator everything he’d done so he was stable enough to know what he was doing,’’ Moon said. “He was frustrated because he didn’t get what he wanted.”

Moon said the case has been tough on his deputies and investigators.

“My two deputies are both young in general and young in law enforcement,’’ the sheriff said. “Obviously it was pretty hard on them because they’ve never experienced anything like that.”

His investigators and supervisors on the scene have about 100 years of combine experience between the three of them, and also were disturbed.

“All three of them said it’s the worst thing they’ve ever seen,’’ he said, “or experienced in their careers.”