The mystery only deepens Judy Schaltenbrand's agony.
Her son, David, was killed in a hit-and-run early Aug. 14 as he tried to cross Mt. Royal Boulevard in Shaler. More than three months later, police still had not tracked down the driver.
"The problem is there is no closure," said Schaltenbrand, 59, choking back tears. "We have to have some type of closure. Until that happens, life is a mess."
Desperate to turn up clues, police are considering hypnotizing a couple of witnesses. That's welcome news to the Schaltenbrands.
"Whatever it takes to resolve this, they should do it," said Dale Schaltenbrand, 34, David's brother.
Shaler Detective Richard Byers said two witnesses crossed the street about the same time as David Schaltenbrand, but they did not offer police much information. Byers thinks hypnosis might help.
That has prompted investigators to call Plum police Chief Robert Payne, who is trained in forensic hypnosis.
Police use forensic hypnosis to help witnesses and victims recall events otherwise lost in memories scarred by trauma.
"In traumatic experiences, such as rape, the human process is to block (trauma) out of the mind," Payne said. "They don't want to relive it."
Hypnosis places a person in a trance state that can resemble sleep, but is instead an altered state of consciousness more like a lucid dream.
Payne was trained in forensic hypnosis in the 1970s -- early in his career as an Allegheny County detective.
"I had just finished college and was looking for something better (in law enforcement) that would be an aid, a tool," Payne said.
While information gleaned from hypnosis can't be used in court in Pennsylvania, it can be a vital tool for investigators, Payne said.
Payne said he has used hypnosis in dozens of cases in his 30 years as an Allegheny County detective.
In perhaps his most memorable case, Payne used the technique to help track down two men later convicted a raping a girl in the woods near Greater Pittsburgh International Airport after abducting her from Stowe.
The girl survived the August 1977 attack, and under hypnosis described her attackers so well that an artist was able to draw sketches of them. She also remembered details about their car.
"She told us what radio station was playing; and she described a knob missing from the door, stains on the seat and garbage in the car," Payne said.
Within a couple weeks, police tracked down the car in McKees Rocks. Subsequently, David Rall and David Schmidt were arrested and convicted, and each was sentenced to about 20 years in prison.
Payne works to establish a rapport and build trust with people before attempting to hypnotize them. He tells them to relax by focusing on something pleasant, then guides them into a hypnotic trance.
"Forensic hypnosis gives (victims) the opportunity to review the event in the third person as if on a screen," Payne said.
Forensic hypnosis training continues to flourish, particularly in an effort to solve cold cases, said D.A. Brady, one of the founding directors of The National Board of Professional and Ethical Standards, an organization that certifies qualified hypnotherapists from around the world.
"Hypnosis is one more investigative tool," Brady said. "It is not meant to be used individually."
The use of hypnosis by police varies widely.
About half of Texas' police officers are certified to use forensic hypnosis, Brady said. New Jersey is more restrictive than other states. State guidelines say sessions should be video or audiotaped, and only the hypnotist and subject should be present, Brady said.
Byers said he is awaiting guidance from the Allegheny County District Attorney's Office before pursuing hypnosis in the Schaltenbrand case.
Meanwhile, anyone with information about the incident should contact Byers at 412-492-2222, ext. 426.
