A Kentucky man says his pit bull attacked his girlfriend. But that's not the whole story.

We want to warn you some of the details in this story are quite disturbing.

Police called it one of the most vicious attacks they had ever seen, an atrocity of rare brutality and cruelty: A pretty young single mother left grotesquely mutilated, beaten beyond recognition and bleeding to death.

Marilyn Stanley, 27, always wears a cap now so that nobody, including herself, can see the disfiguring scars of her ordeal.

"I don't look at myself in the mirror with my head uncovered," said Marilyn.

She used to have a full head of beautiful blond hair, and was living a happy life raising a young son on her own in Burlington, Kentucky. That is, until she met 31-year-old Zachary Gross. The two began casually seeing each other. Within months, it had turned into a serious relationship.

Marilyn's mother Linda didn't approve.

"There was something I didn't like about him," Linda said. "I didn't trust him. I didn't think he was any good."

And sure enough, Marilyn says Zach would soon reveal himself to be jealous, possessive and controlling. She says Zach started to get mean.

"The first time it was getting put outside of his house," said Marilyn.

And she says he grew increasingly more violent and abusive.

"It went from that to being pushed down front porch steps," said Marilyn.

Soon Zach was beating Marilyn regularly, she says.

"I got a broken nose and two black eyes," said Marilyn. "After that I got choked out.

"I told him 'Dude, you said you were going to kill me -- I'm done,'" said Marilyn.

But Zach wasn't about to let Marilyn go without a fight, texting her repeatedly. Just before the scalping, he wrote, in part:

"To: my love/bff/soulmate/lover: I hate hate hate that u r scared of me cuz u shouldn't have to b scared of the one u love ... i am here to protect u and give u all that u need an everythin u need and than some i love u wit all my heart"

"He'd been telling me for like days over texts that he wanted to talk to me," said Marilyn.

And when Marilyn refused, she says an obsessed Zach started stalking her, following her everywhere she went and even getting a job at the same book warehouse where she worked.

Marilyn says Zach got so crazy over her rejection of him that he turned up on her doorstep at 6 a.m. one day.

"So I open the door and just get punched in the face," said Marilyn.

And when Marilyn screamed for help, she says he got even crazier.

"He jumped on the roof of my car until it caved in," said Marilyn. "He got his tire iron and smashed out my windshield and my back window."

Marilyn says she was afraid Zach might kill her if she called the police.

"It didn't seem like he was going to stop," said Marilyn.

Marilyn finally agreed to meet with Zach in a desperate attempt to calm him down.

"I literally didn't know what else to do," said Marilyn.

The moment she walked through the door of his home in September 2015, she says she was greeted with a sucker-punch to the face.

"And I asked him what that was for, and he brought up pictures of me and my son taken at a park," said Marilyn. "It was because another guy had taken the picture and posted it and tagged me on Facebook."

And she says Zach continued to beat her up.

"I turned my back to him so he would be punching me in the back of the head and not in the face," said Marilyn. "And then I ran for the door. But he picked me up and I was like mid-air trying to throw myself down to the ground so I couldn't be dragged into his room."

Marilyn says she feared she might not get out of that room alive.

"And I grabbed on to the door frame," said Marilyn.

Marilyn Stanley was about to be plunged into an unspeakable living nightmare.

"Next thing I know I'm on the ground in front of the closet being straddled across my waist, and my arms are pinned down directly at my side," said Marilyn.

Marilyn says that as Zach Gross continued to hit her, she managed to grab a knife she'd brought with her in case she had to defend herself against him.

But before she could use it, Marilyn says, she suddenly had a second attacker on top of her: Zach's pet pit bull "Capone."

The dog then bit off most of her right ear. And Zach continued to hit her.

Marilyn was suddenly unconscious.

"The next thing I remember is sitting up," said Marilyn. "The dog was gone and Zach was kneeling in front of me, kind of like smirking. And he said 'Look at you, you're bald. Now nobody's going to want you. Go look at yourself in the mirror.'"

Marilyn was too afraid to look.

"I didn't look in the mirror when he told me to. I looked kind of in the direction of it, but past myself," said Marilyn. "I could just see blood and my hair was wet, and I didn't really think that my scalp was completely gone because I don't remember it being cut off. I thought maybe some of my hair got maybe in splotches ripped out or something."

But Marilyn says Zach wasn't finished with her yet.

"He kicked me in the stomach and he told me to lay on my side," said Marilyn. "He goes, 'I'm going to break your ribs,' and he stomped down on my ribs. They didn't break. He stomped on my ribs again, and I heard them crack, but I didn't feel it at that point."

She endured this for two hours. Marilyn says Zach Gross's brutal bloodlust was finally satisfied.

"He helped me wipe the blood off my face and told me 'It's OK. He's done. He's not going to hurt me anymore,'" said Marilyn. "I asked him to call an ambulance but he said no because they would take his dog."

Instead, Marilyn says Zach gave her a T-shirt to cover her wounds and a hoodie to put over her head, then handed her a plastic shopping bag.

"And I said, 'I don't want this. What am I going to do with this?'" said Marilyn. "I didn't know it was my scalp."

He didn't take her to a hospital.

"No, he drove me to the street past my mom's house," said Marilyn.

It was there where Marilyn's attacker would add the ultimate insult to her injuries.

"He even asked me if he could have a kiss when he dropped me off," said Marilyn.

"All I felt was the weight of my ear, so I was propping it up in my hand," said Marilyn. "I didn't feel like I had cracked ribs, I didn't feel like my scalp was gone. I didn't feel like my face was three times its size."

"She held the bag up when she came into the yard and said, you know, 'My hair's in this bag,'" said Marilyn's mother Linda.

It wasn't until the EMTs got Marilyn to hospital that her mother learned to her horror that nearly half her daughter's scalp was in that bag.

"When somebody says that somebody was 'scalped,' I mean it's like unheard of in this day and age, really?" said Linda.

Marilyn was barely conscious when she was told she'd been scalped alive.

"I remember the doctor coming in to tell me that my hair's never going to grow back," said Marilyn Stanley.

Marilyn's life had hung in the balance as she underwent emergency surgery to repair a severed artery. And she would undergo several more operations before doctors finally succeeded in patching her back together with skin grafts from her leg.

"The whole thing is a scar. My whole upper thigh," said Marilyn.

It was a miracle that Marilyn Stanley was still alive after being beaten, mauled by a pit bull and scalped by the man she once called her boyfriend.

But despite a mountain of evidence against him, Zachary Gross denied he scalped and disfigured her, blaming the hideous crime on his pit bull.

"The news said I held a girl down and scalped her hair off, but it's been proven now that my dog did that," Zach said in a phone interview with a nationally syndicated radio show. He called in from jail after his arrest to declare his innocence.

"They arrested me before they even got a statement," Zach said on the show.

"It's so stupid I just can't even think to respond to it," said Marilyn.

And Boone County, Kentucky Sheriff's Detective Brian Cochran says the evidence immediately spoke for itself.

"Right out of the gate we had suspicions that it wasn't just a dog-bite case," said Det. Cochran.

Investigators who searched Zach's home found a trail of blood leading from his bedroom where Marilyn was scalped to the bathroom where he had tried to force her to look in the mirror.

"It was on the floor, on the walls, it was in the bathtub, it was on the towel rack," said Cochran.

But the most incriminating piece of evidence was a pink knife found in a dresser drawer, covered in blood, with blood and hair on the knife, according to Cochran.

"So our argument was that he was hiding the knife," said Boone County Commonwealth's Assistant Prosecutor Leanne Beck.

It is the same knife that Marilyn had put in her pocket for protection when she went to her abusive ex-boyfriend's home the day she was attacked, but that she'd dropped while he had her pinned on his bedroom floor beating her.

"Our theory was that when Zachary Gross got possession of the knife, he used it on her," said Beck.

Investigators would also learn that Zach Gross had a lengthy rap sheet of violent crimes committed against other women.

"Including two assault in the fourth degrees, one domestic violence, the other one spouse abuse," said Beck.

Assistant Prosecutor Beck says the only hole in the case against Gross was that Marilyn was unconscious during her actual scalping.

"That's the part she does not remember," said Beck.

The last thing Marilyn recalls is lying on the floor with both Gross and his pit bull Capone on top of her, him punching her and the dog tearing off part of her right ear.

"Other than that the dog didn't do anything else," said Marilyn.

Investigators say Marilyn's other injuries appeared to have been inflicted by a dog's teeth.

"The scalp injury was more consistent with a knife than with a dog," said Det. Cochran.

That finding would be supported at Gross's trial by Dr. William Kitzmiller, who operated on Marilyn's scalp.

"The multiple injuries to the scalp were so severe that re-plantation was not a reasonable option," Kitzmiller said on the stand. "Because of the straight nature of the edges, it seems to me more favoring a sharp object rather than a dog bite."

The doctor's testimony was a crushing blow to Gross's defense team.

"That was the defense's theory the entire trial, that it was a dog attack," said Beck.

And Marilyn herself took the stand at Gross's trial. Marilyn also stepped down from the stand to show the jury her horrific scalping wounds.

"This was really hard for her, but I think that it had a huge impact on the jury to see the permanent disfigurement he caused," said Beck.

The only one apparently unmoved by Marilyn's testimony was Gross.

"He did not seem very remorseful about what he did to Marilyn," said Beck. "He made a gesture with his hands that was not appropriate for court. The judge held him in contempt for that action."

The jury quickly returned a verdict of guilty of assault in the first degree. Assistant Prosecutor Marilyn Beck asked the judge to give Zachary Gross the maximum sentence.

"Twenty years is what's appropriate for de-scalping a human alive," Beck said in court.

But Gross remained unrepentant at his sentencing hearing, still proclaiming his innocence.

"I wanted to go to trial so that everybody could hear that Marilyn never said I cut her hair off. Marilyn never said I told my dog to attack, and I feel horrible for what happened,'" Gross said. "I feel that the verdict was wrong."

The judge didn't, sentencing Zach Gross to the maximum 20 years behind bars, plus another 34 days for contempt of court.

After sentencing, Zach Gross called Crime Watch Daily from behind bars, still echoing his defense, claiming his dog did it.

"Marilyn has never once ever said that I cut her hair off. That was just a doctor's belief that I cut her hair off," said Gross.

CWD: "Did you or did you not scalp Marilyn Stanley with a knife?"

Zach Gross: "Oh, absolutely not."

Marilyn's mom Linda still isn't buying it, claiming she would have handed down a much harsher sentence.

"I just wish it would be life because I don't want him to ever get out," said Linda.

For the sake of Marilyn Stanley, who is already living in fear of the day Gross is eventually freed.

"I don't think anything could make somebody not afraid," said Marilyn. "He's a sociopath. He doesn't feel remorse for anything that he's done to anybody."

Marilyn is reminded of what Zachary Gross did to her every day, but she still stands tall.

"He hasn't gotten me, and he won't," said Marilyn. "He hasn't gotten my pride, he hasn't gotten my life, and I won't let him"

Gross has filed an appeal. His pit bull Capone was ordered by the judge to be euthanized. Capone remains in an animal shelter awaiting the outcome of that appeal.