WALLKILL, N.Y. (PIX11) — Nineteen years ago, the battered body of 20-year-old Megan McDonald was found on a dirt path in Wallkill, Orange County.

Paul DiGiacomo, president of the Detective’s Endowment Association in New York City, only recently learned the cold case murder victim was the daughter of a former, NYPD investigator, Dennis McDonald. He viewed the crime scene photos and told PIX11 News Megan McDonald suffered brutal head injuries.

“They were horrifying,” DiGiacomo said, “even to a seasoned detective like myself with 39 years on the job.”

DiGiacomo got in touch with the New York State Police, where Major Crimes investigator Brad Natalizio has reviewed a thousand tips in the case. McDonald was a SUNY Orange college student working her way through school with a waitressing job at the American Café in the Galleria Mall.

“This case is unique in nature,” Natalizio told PIX11 News, “because the level of violence we saw inflicted on Megan is something I’ve never seen in any other case.”

The student’s father had retired from the NYPD in 2000 and died suddenly in 2002, at the age of 47. Megan McDonald’s older sister, Karen Whelan, said there was “no warning.”

McDonald’s sister is now aware that investigators have a prime person of interest they’re poised to arrest in the student’s murder if they get a witness to come forward to corroborate their evidence, which includes DNA.

“We don’t want to convey that we’re sad anymore,” Whelan told PIX11 News over the phone. “We want this killer to know that he’s a coward. He attacked my sister from behind. He was a coward, and he can’t keep hiding.”

Investigator Natalizio said the first suspect back in 2003 was one of McDonald’s ex-boyfriends, but “this original suspect has been eliminated and we have a new person of interest in this case.”

Natalizio said people living in Wallkill and Middletown in Orange County need to erase the narrative they’ve heard about the case for so many years and consider the new evidence state police have accumulated. The Detective’s Endowment Association is offering a $10,000 reward for information that leads to an arrest, and the FBI is offering another $10,000.

Last year, investigators did a recanvass of residents who lived at the Kensington Manor apartments in Walkill, where McDonald’s white Mercury Sable was found abandoned on March 14, 2003, the date she was actually killed.

One resident of the complex told them she recalled something very specific about the early hours of March 14 that year: a Honda Civic that had a loud sound system. Natalizio said the hatchback “was observed following Megan’s vehicle the night of the homicide in the Kensington Manor area.”

“This information is important because it’s consistent with a person of interest who did operate a vehicle back then of that style,” Natalizio said.

The state police investigator said the man with the loud sound system got into Megan McDonald’s Mercury with another man. They drove off and were hanging out near Bowser Road in another part of Wallkill.

Natalizio said Megan was attacked in her car with a blunt object.

“The evidence revealed she was killed in the driver’s seat of her Mercury Sable,” Natalizio told PIX11 News, “at the crime scene, at Bowser Road, and that she was left — she was dumped — out of the car.”

The two men then drove McDonald’s vehicle back to the Kensington Manor complex. One of the men who was in the car died in recent years; Investigator Natalizio said he was tormented by what he witnessed inside the Mercury.

The other man is the prime suspect.

The FBI did a behavioral profile of the suspect and concluded he was a manipulative narcissist.

“He’s a very controlling individual,” Natalizio said, “and we believe that’s why we haven’t gotten the cooperation of the community.”

The state police want the suspect’s friends to know they’re not a target of this investigation. The state police investigator said the suspect had been intimidating members of his inner circle for years, keeping them quiet about what they know.

“We’re here to tell these individuals they’re not going to be in trouble,” Natalizio said. “We support them.”

Natalizio said what happened to Megan McDonald to “intimate partner violence.”

“It’s a crime of rage,” DiGiacomo confirmed.

State police have a very good timeline of Megan McDonald’s final day alive. The young woman worked until 3 p.m. at the American Café, and then went to the bank. At 7 p.m., McDonald drove by a party at Greenway Terrace in the Town of Wallkill. She was invited in but told some friends she was visiting another friend in Middletown.

At midnight, Megan McDonald left Middletown and drove back to Wallkill in the early minutes of March 14, 2003. She briefly returned to Greenway Terrace, but then left. At this point, the Honda-style hatchback was seen following McDonald’s white Mercury near Kensington Manor. Two men then got into McDonald’s car.

It’s believed Megan McDonald was killed in the early hours of March 14, 2003. Her body wasn’t found until 1 p.m. the next day near Bowser Road. Her mother was trying frantically to reach her on the phone.

Karen Whelan wants people to remember her sister for her light.

“Megan was amazing,” Karen Whelan said “She’d really light up a room. She just made everybody feel comfortable.”

Whelan and her husband said they know Megan McDonald, a “spitfire,” was standing up for herself before she died.

“We’re proud of her,” Karen and James Whelan said.

And they’re grateful that law enforcement from multiple agencies will pick up the fight for justice their father couldn’t do.

“The fact that his police brothers and sisters are helping to carry on in his place, for his daughter, means everything,” Karen Whelan said.