Dating app murder suspect seemed like a 'dream guy' at first, ex-girlfriend says Danueal Drayton's last words to her were, "I'm gonna kill you," she said.

A New York City woman who dated the 27-year-old suspected murderer whom police believe used dating apps to target his victims said he seemed like a "dream guy" at first, but that facade eventually faded when he allegedly attacked her six months later.

Zynea Barney, 26, said she began interacting with Danueal Drayton last November after he messaged her on an online dating and matchmaking application, for "two days straight."

Barney "wasn't looking for love" at the time, so she said she ignored the messages at first, but she eventually replied.

"It was just conversation, you know, just talk here and there," Barney told ABC News.

Barney and Drayton were soon texting every day, and three weeks later, their conversations evolved to phone calls, she said. At the time, she says she found him to be a "real good guy" with his "head on his shoulders."

Drayton stood out because instead of asking Barney for photos of her body, like a "normal guy" would, he would inquire about her goals and dreams instead, she said.

"We would talk all night, all day, regular conversation," she said. "No red flags, nothing. Just you know -- the perfect guy."

Barney's first impressions of Drayton were positive because of "the way he spoke," she said.

"He carried himself very well in conversation," she said. "Like, he showed that he was very interested in what you talked about, what you had going on."

What Barney first perceived as interest later translated into what she felt was him "pretending to have similarities" with her, which is what "kept the conversations going," she said.

"It was a delight to talk to him at that time," Barney said.

The first time the pair met in person, they stayed in a hotel together but slept in separate beds, Barney said. That night, they watched movies and joked around with each other.

Then, Barney and Drayton began seeing each other every day, she said, whether it be a walk in the park or going out for a meal.

"There was not a day we didn't see each other," Barney said.

Barney said the relationship "kept going forward in a positive direction," but she noticed something amiss when Drayton was driving her car and she answered a call on his phone from a woman named "Cherry."

Barney says the woman told her that she also met Drayton on a dating app. According to Barney, the woman said she and Drayton were "just friends," but told Barney he'd never mentioned that he had a girlfriend.

Barney demanded that Drayton pull over and get out of her car, causing him to plead with her, telling her that the woman was "nothing" but "conversation," she said.

But, Barney says she drove away, telling Drayton that while he should have been honest with her, they could remain friends since Drayton was "new to New York," offering him help with looking for a job. Barney's son was in the backseat of the car at the time, she said.

After that, the relationship spiraled out of control, Barney said. She began to feel threatened in early June, she said, when Drayton would allegedly sleep outside her home, waiting for her and begging her to take him back when she would ask him to leave.

"He then proceeded to take my landlord's ladder that was placed in my hallway and place it to the window and climbed up," Barney said, adding that her son was in the room at the time. "That's when I knew, like, he has to go."

During their final encounter, Drayton allegedly strangled Barney, she said.

That day, Drayton began "blowing up" Barney's phone around 6 a.m., she said. Around two hours later, when she finally picked up, Barney said he asked if he could see her before he went to California for a job.

After the pair went to Chipotle together, Barney says Drayton told her that he wanted to spend "the rest of the day" with her. Barney said she informed him that she had things to do and asked Drayton where she should drop him off.

Once they got to the park where Drayton requested to go, Barney said he asked her if she could see them getting back together in the future.

"I was like, 'No, not at all,'" Barney said. "I said, 'I told you this over and over. It's not like I led you on. I'm doing the right thing. I told you, like, I just don't want to be with you at this point no more. I just don't have time for little games. Let's just separate, be friends. We can hang out time to time.'"

Drayton then "got quiet" before saying "OK" and exiting the car, Barney said. He then began digging in his pockets before he allegedly lunged at her, she said.

"And that's when he just looked at me in the car and then jumped across, had both of his knees on top of my knees while my seat belt was still on," she said, adding that Drayton somehow pushed her gear into park before he attempted to strangle her.

Barney claims Drayton told her over and over again, "I'm gonna kill you."

Barney said she went into "survivor mode," before clicking the button to release her seat belt and opening the driver's side door. Drayton then allegedly took one hand off of her neck in an attempt to close the door, but Barney said she "threw" herself outside of the car.

Drayton then allegedly hopped outside of the car on the passenger side, but Barney said before Drayton could get to her, three factory workers approached her, asking if she was OK.

The workers then chased Drayton off after he kept "charging toward" her, Barney said. Drayton's last words to her were, "I'm gonna kill you," she alleged.

Police then arrived on the scene and saw that Barney had swelling on her neck, she said. She says she refused medical attention, telling officers she just wanted to get to her son at his day care but let them photograph her injuries and write a report.

After picking up her son, police escorted Barney home so she could pick up some belongings and drive to a friend's house -- a location that Drayton didn't know about, she said.

Barney said she still has a mark on her throat from where Drayton allegedly dug his thumb into her.

Barney claims every day after that, Drayton would call her, vacillating between apologizing and allegedly threatening her in voicemails.

"You kept seein' different personalities through the voicemail," she said.

Police arrested and jailed Drayton days after he allegedly assaulted Barney, she said. She didn't know that he had been released from jail in New York until last week when the NYPD announced that he'd been arrested on different charges in California and was a suspect in the murder of a nurse in Queens, New York.

Barney says no one at the police department or district attorney's office reached out to let her know Drayton had been released.

She then became scared for her the safety of her son, whom Drayton had spent a fair amount of time around, she said. Barney's son would even call Drayton "Dada" sometimes, she said.

The NYPD did not immediately respond to ABC News' request for comment on Barney's case.

Drayton, who is from New Haven, Connecticut, was arrested in Los Angeles on July 24 for allegedly sexually assaulting and trying to kill a woman there, NYPD officials announced after the arrest.

He was apprehended in North Hollywood while allegedly strangling and sexually assaulting a 28-year-old woman whom he refused to let leave after a date, according to the Los Angeles County District Attorney's Office.

Drayton had been wanted in New York as a suspect in the murder of a nurse, who was found dead in her home in early July, the NYPD said.

The "common denominator in these cases -- one being a murder and one being a rape -- is dating websites," NYPD Chief of Detectives Dermot Shea said last week. "This individual is known to us and believed by us to be using dating websites to meet women and victimize women."

In California, Drayton was charged with attempted murder, forcible rape, sexual penetration by foreign object and false imprisonment, Los Angeles prosecutors said. His bail was set at $1.25 million.

Since in police custody, Drayton has claimed to have murdered up to seven women nationwide -- all of whom he said he met on social media, police sources told ABC News.

Drayton has claimed that three of the murders took place in New York, the police sources said, although no evidence has emerged to validate Drayton's claims.

ABC News' Cathy Becker, Aaron Katersky, Meghan Keneally and Emily Shapiro contributed to this report.