MONTGOMERY COUNTY, Md. (WUSA9) -- Kathy Beatty's bedroom is exactly how she left it nearly 40 years ago.
The red-headed, freckled-faced 15-year-old went went out one summer night and never came home.
"What happened to Kathy that night? What did they do and why?" asks Pat Haberman, Kathy's mother.
For nearly four decades, those questions have haunted Haberman.
On July 24, 1975, Pat left their Montgomery County house for a few hours. While her mother was out, Kathy was supposed to stay home but, as many her age would do, she went out anyway.
"We don't know where exactly. Pat went looking for her and eventually Kathy never came home," said Steve Kerpelman, a private detective with SMK Investigations.
Kathy's older sister found her the next day, beaten unconscious in what was then a heavily wooded area by a K-Mart store just off Georgia Avenue in the Aspen Hill area of Montgomery County. Those woods were a local hangout for teens at the time and about a mile from Kathy's house.
Eleven days later, Kathy died from her injuries. Thirty-nine years later, still no answers.
"She was such a sweet girl, everybody liked her," recalled Haberman. "To think that my daughter was murdered 39 years ago and this case hasn't been solved it just doesn't make sense," she said, through tears. "Other cases get solved, why can't Kathy's get solved?"
Kathy's case hits close to home for two men working it. Kerpelman, who went to school and had classes with Kathy as well as Frank Colbert, a detective with the Montgomery County Police Department's cold case division, who grew up in the same neighborhood.
Kerpelman, a former police officer with the Prince George's County Police Department, has spent the last six years as a private detective working Kathy's case.
His investigation is separate from the cold case file at the Montgomery County Police Department and, as the two admit, it's uncommon for police departments to work with private detectives but Kerpelman and Colbert work close together and share information about the case when they can.
Because of Kerpelman's close work and dedication to Kathy's case, "He came highly recommended by my predecessor," said Colbert, who recently took over the case in the cold case division.
Perhaps it's all too fitting that two men who knew, grew up and went to school with Kathy Beatty are now charged with solving her murder.
"When Kathy was killed, it was something that nobody forgot," recalled Kerpelman.
Especially her mother, who often pictures a life that could have been.
"She didn't have a life she only made it to 15 and they took it away," said Haberman. "It's very hard to live with. All these years. I have my cries. I have my days," she said.
It has proven difficult to live with and difficult to solve.
Kerpelman attributes some of those difficulties to "A lot of rumors, a lot of things out there that may be true, may not be true but get perpetuated."
Still, Kerpelman and Colbert are encouraged because of a new effort to get Kathy's story back in the public consciousness. Colbert said Montgomery County Police recently ramped up resources in their cold case division. Now, he and Kerpelman are both beginning to receive tips again about Kathy's case.
Colbert said they are looking at old evidence with a new eye.
"Part of our job in cold case is to reexamine all that evidence and see what new technologies we can apply," explained Colbert. "The people that were responsible, that were with Kathy that night are still likely in the area," he continued.
"They've been free all these years? That's a long time. They're just walking around like everybody else and my Kathy is in her grave. That's not right," said Haberman.
But this mother hopes, somehow, it still can be right.
"This is it, this is the final chapter. It's going to be solved," said a hopeful Haberman.
On Friday, July 25, 2014 at 7:30 p.m., a vigil will be held for Kathy Beatty, where she was found beaten unconscious, on the side of the Aspen Hill K-Mart parking lot, right along the wood line.
If you have any information on Kathy Beatty, you're asked to call Montgomery County Police at 240-773-5070 or visit www.whokilledkathy.com.