In Maryland, there is a new push to help solve one of the state's most troubling murder mysteries ever.

Julie Ferguson had just got off her shift at work and was waiting for her friends to pick her up in March 1995. But police believe she got into another car -- one with a killer inside.

Ferguson, 17, was later found strangled, with her throat slashed. Baffled cops have been unable to catch the beast who killed Julie Ferguson.

A shadow of suspicion has always hung over one man, whose family says he's vanished. Now the most unlikely victim in this murder mystery is begging him to come forward: His own daughter. She's desperately trying to find her father in the hope she can persuade him to come back and clear his name.

Julie, 17, was a popular high school senior in Greenbelt, Maryland, on the outskirts of Washington, D.C.

Remembering Julie brings tears to the eyes of those who loved her. Her mother Pat remains so grief-stricken she finds it difficult to even talk about her daughter.

Some of Julie's friends were supposed to meet her around 10 p.m. on March 20, 1995, after she got off her after-school job at a Greenbelt strip mall. But Julie's friends only found her belongings where she had been seen waiting for them to arrive just minutes earlier. Her panicked friends notified her mother and the police.

"It became a murder investigation about seven and a half hours later," said Prince George's County Police Det. Bernard Nelson. That's when a passerby found Julie's body in a park about five miles away at 5:30 the next morning.

"Her throat was cut and it was later determined that she died from strangulation," said Det. Nelson.

Homicide Detective Nelson says there was no sign of robbery or sexual assault, but there were reportedly bruises on Julie's hands that indicated she'd struggled with her killer. Her friends were distraught, and terrified there was a maniac on the loose. The entire community of Greenbelt was on edge.

Witnesses reported seeing several suspicious vehicles at the strip mall where Julie was last seen alive.

"One that stuck out in particular was described as a burgundy or red Volkswagen Jetta that was occupied by two black males and a black female who were seen actually conversing with Julie before she disappeared," said Nelson.

That car and the people inside it were never located. But police nonetheless believe Julie was probably taken by somebody against her will. Police questioned a spurned admirer.

"He was considered a suspect because he made a number of passes at Julie, which she rejected, which he didn't take very well," said Nelson. That suspect was later convicted of a separate homicide and is now behind bars.

"We've talked to him on numerous occasions, even as recent as earlier this year, but at this time we have nothing to actually prove that he was involved," said Nelson.

Then there is Doug DeSilva, a local auto mechanic who had previously been arrested and locked up in the rape of a woman not far from where Julie was found murdered.

"We subsequently interviewed him a number of times," said Det. Nelson.

He was eventually released, cleared by DNA. But police believe he's still somehow connected to Julie's case.

"He didn't have a solid alibi of where he was at that time," said Nelson. "He provided some statements that would indicate that he could possibly be involved, but nothing that would actually push it over the edge where we can charge him."

Crime Watch Daily wanted to talk to DeSilva. But we learned he was nowhere to be found. But we did locate his daughter April, who told us she and her family have not seen nor heard from him for 16 years.

April has been searching in vain for her father, who she says appeared to vanish off the face of the Earth several years after the murder of Julie Ferguson.

"I've contacted all kinds of people. I've contacted Social Security. I have a whole file of places I've contacted about this," April said.

April finds it hard to believe her father would have murdered Julie. Now she is pleading for him to come forward to prove his innocence and clear his name.

And Julie's still-grieving mother is pleading for anyone who knows anything about her daughter's murder to contact police and help them finally solve the case.

"Somebody out there knows something and I just wish they would come forward and tell their story," said Julie's mother Pat.

Julie's high school friends have a Facebook page they hope might attract some leads, as well as keep Julie's memory, and case, alive.

A reward of up to $25,000 is available for information leading to an indictment or arrest in the case.

Anyone with information is urged to contact Prince George's County Crime Solvers at (866) 411-TIPS. Tipsters can remain anonymous.