Due to the shared location and other similarities among the deaths, law enforcement officials viewed them as the work of a possible serial killer. But since the first one took place in October 1986, the murders have all remained unsolved.
Now, the cases are getting renewed attention, and officials say that new tools give them a shot at finally solving the two-decade-old puzzle.
"We are very hopeful that today's technology -- advancements in DNA testing and analysis -- and a fresh look at the evidence will lead to a successful conclusion," Alex J. Turner, special agent in charge of the FBI's Norfolk, Va., division, told AOL News. Along with sending fingerprints and trace evidence for testing, the bureau has doubled the reward it is offering for fruitful tips.
The Virginia State Police are also re-examining the cases and the pathological agenda that may link them.
"Any time you have multiple crimes within close geographic proximity and there are similarities between those crimes, you have to be open to the possibility that those crimes are related," said Virginia State Police Special Agent Keenon Hook. "You pursue every reasonable hypothesis and logical conclusion, and that is what we are doing."
When investigators first started digging into the Parkway Murders, said Turner, they put together a suspect list that eventually ran to 100 people. "Many of those were eliminated initially. But we are starting with the entire list of individuals and going back through them again," he said, as officers search for the killer, or killers, responsible for the chilling crimes that took place two decades ago in a historic corner of the Old Dominion State.
Bodies One and Two
Cathleen Marian Thomas was a 27-year-old native of Lowell, Mass. She had graduated from the U.S. Naval Academy and was working as a stockbroker in Norfolk.
"I know people use the expression 'the best and the brightest' pretty frequently, but my sister was that kind of person," Cathleen's brother, Bill Thomas, told AOL News. "She was brilliant and beautiful."
According to Bill, Cathleen had recently started dating Rebecca Ann Dowski, a 21-year-old business management major and standout softball player from the College of William and Mary in Williamsburg.
"Rebecca was a lot like Cathy," Bill said. "She was very attractive, very accomplished."
On the evening of Oct. 9, 1986, Cathleen and Rebecca had been hanging out with two friends at a computer lab when they left to spend some time together. What happened to them after that remained a mystery until three days later, when a jogger running along the York River by the Colonial Parkway spotted Cathleen's white Honda Civic on the edge of an embankment.
"When the first officer on the scene reported there, he thought they were dealing with a traffic accident," Bill said. "So he went down and smashed the back window. It was then that he saw the mess inside the car."
Rebecca was found in the back seat. Cathleen was stuffed in the hatchback's storage area. Both women had been strangled, and their throats were cut. The injuries to Cathleen were so extreme that she was nearly decapitated.
The perpetrator had attempted to set the Honda on fire using kerosene or diesel fuel -- several matches were found scattered around the car -- and when that failed, he apparently tried to push the vehicle over into the river, only to have it snag on the brush.
Both victims' purses and money were found inside the car, and the county medical examiner found no signs of sexual assault.
The possibility that they had been targeted for their sexuality led to speculation that the killing might have been a hate crime. But less than a year later came evidence that another motive could have been at play.
"That Was How We Found Out: Watching TV"
Virginia authorities found themselves in the middle of a second double homicide when the bodies of David Lee Knobling, a 20-year-old man from Hampton, and Robin M. Edwards, a 14-year-old girl from Newport News, turned up in the Ragged Island Wildlife Refuge the following fall.
"On Sept. 19, 1987, my sister had gone out on a date with David's cousin," Janette Santiago, Robin's sister, recalled in an interview. "They were supposed to go see a movie, so I guess David volunteered to take them. He had a little truck, so the boys let Robin sit upfront. They must have hit it off, because David dropped her off at the house and then came back to pick her up after he took everybody else home."
As in the case of Cathleen and Rebecca, a jogger alerted police to the scene.
David's pickup was found near the wildlife refuge at the foot of the James River Bridge. The keys were in the ignition, and David's wallet was on the dashboard. Items of clothing belonging to both David and Robin were also in the car.
There was no sign of struggle at the scene, and it was unclear whether the couple had met with foul play until their bodies washed ashore downstream. Both had been shot in the back of the head.
"Earlier that day, my parents had given an interview to the media, asking my sister to return home, so we were all sitting around the TV expecting to see that interview," Janette recalls. "Then, boom, here comes the headlines. ... That was how we found out: watching TV."
While there were some differences between the killings of Thomas, Dowski, Knobling and Edwards -- particularly in the killer's methods -- the commonalities meant a connection could not entirely be ruled out.
A Tragic First Date and a Deepening Mystery
Roughly six months later, the headlines would once again be dominated by another, and similar, case.
Richard "Keith" Call was a 20-year-old college student on April 9, 1988. He had big plans for the night: He was embarking on his first date with Cassandra Lee Hailey, an 18-year-old woman from Grafton.
"They shared a class or two at college," said his sister, Joyce Call-Canada. "Keith picked her up, and they headed over to a cookout in Newport News. They stayed there until sometime between 1 a.m. and 2 a.m."
Approximately eight hours later, on April 10, Call's vehicle was found abandoned at the York River Overlook on the Colonial Parkway.
Keith and Joyce's father, Richard W. Call, was one of the first people to spot the car as he passed it on his way to work. Not noticing anything overly out of the ordinary, he figured Keith might have left it there to jump into a friend's.
"His mind just didn't go to something terrible, and he went ahead to work," Call-Canada said.
Later that day, Keith's father received a call from park rangers, who had encountered a very different scene.
"The rangers said the door was wide open and the keys were lying in the car," Call-Canada said. "They also found Keith's wallet, glasses and watch in the car, along with Cassandra's purse, bra and just one of her shoes.
"We just don't know how that stuff got back in [the car]. The only thing we could think of was that the killer came back and put them there," she said.
Multiple searches were conducted for Keith and Cassandra, but no other trace of them has ever been found.
Less than two years later, two more families would lose loved ones in the same area.
Found Side by Side
"My sister, Annamarie Phelps, had just turned 18," Rosanne Phelps said. "She had a boyfriend who was a little younger, and he had a sister who lived at the beach, and they wanted to move to her house."
A friend of Phelps' boyfriend, 21-year-old Daniel Lauer, was also moving into the beach house, and over Labor Day weekend in 1989 she helped him pack up his belongings.
"We didn't hear anything from them the next day," said Phelps. "We tried to contact them, [and then] we learned that Daniel's car had been found parked at a rest area on the westbound side of I-64."
The case fit a pattern investigators had encountered before: Lauer's keys were found in the ignition, and items of clothing belonging to both of them were found inside the car. Annamarie's purse was left untouched.
Several searches were conducted but failed to uncover any signs of the young couple.
"I remember the weather was really bad, and there was a lot rain," Phelps said. "I remember praying and crying, 'Please don't let my sister be out there in the rain.'"
That October, a hunter came upon the couple's skeletal remains less than a mile from the rest area where Lauer's car had been found.
"They were found side by side," Phelps said. "My sister was wrapped in a blanket. They had been stabbed, and my sister had defensive wounds, suggesting she had fought very hard for her life."
Controversy Yields New Momentum
As the Colonial Parkway Murders went unsolved, they became a source of controversy.
In 1997, Phelps' parents filed a lawsuit against best-selling author Patricia Cornwell, who at one time had worked at the medical examiner's office that had handled the killings of Lauer and Phelps. They claimed that she'd obtained a copy of the autopsy report and included previously unreleased details of their daughter's death in her novel "All That Remains," which Cornwell's Web site describes as the story of a killer who targets "attractive young couples whose bodies are inevitably found in the woods months later."
The couple said the book violated their privacy and caused emotional pain. A judge later dismissed the case.
The unsolved slayings made headlines again in 2009, when authorities were notified that a number of crime scene photographs regarding the Colonial Parkway homicides had been "inappropriately taken" from the FBI's Norfolk office. The photographs were being used as a training tool for a security company, and a number of the images had been leaked to the media.
"There were 84 graphic photographs in all," Bill Thomas, brother of Cathleen Thomas, said. "This security school, for whatever reason, apparently felt that students in their security program could benefit from viewing them."
An investigation was launched, and in December 2009, Special Agent Turner held a press conference during which he said the photos had been taken without approval by a "former non-agent" employee. Turner added that the employee had since died but that the FBI had seized all copies of the photographs from his estate, the civilian training agency and two other individuals.
As unsavory as the crime scene photos revelation was, it appeared to kick the investigation of the homicides back into high gear. Almost immediately, Special Agent Philip J. Mann announced the FBI was conducting a "top-to-bottom" review of the cases in its jurisdiction: those of Cathleen Thomas, Rebecca Dowski, Richard "Keith" Call and Cassandra Lee Hailey.
Other Gruesome Connections Explored
Over the years, some have speculated that there could be a link between the eight Colonial Parkway murders and still other killings.
One is the Route 29 stalker case from 1996, in which a man in a pickup truck flagged down young women, told them something was dangerously wrong with their cars and offered them a ride. One, Alicia Showalter Reynolds, apparently accepted, and wound up murdered.
A second -- and, experts say, more credible -- candidate is the Shenandoah Park murders.
"There are striking similarities," said Chris Yarbrough, a computer programmer who operates a Web site devoted to the Colonial Parkway murders.
In 1996, the bodies of two women, Julianne Williams, 24, and Lollie Winans, 26, were discovered in one of the park's campgrounds. As with Dowski and Thomas, their throats had been slit. As with the earlier victims, both were strong athletes, yet there were no signs of struggle.
Special Agents Turner and Hook won't comment on individual cases, but both agree anything is possible.
"[It] is purely conjecture," Turner said. "[But] I will tell you [that] our investigator, along with the investigator from all of these homicides, have and will continue to share notes and determine whether or not there are any ties."
Profiling the Possible Killer
In an effort to determine if all of the Colonial Parkway cases are indeed connected and whether some of the other cases could be tied in, AOL News asked an expert to look them over and share her opinion.
"What I find particularly unusual about the murders is that, each time, there were two victims," said criminal profiler Pat Brown. "This is quite rare for serial killers; they usually pick one isolated, smaller individual whom they can overpower. This killer or killers had to deal with two, which is much more work.
"Clearly, the killer was armed. Even if we did not have evidence that anyone was shot during the assaults, a gun would be necessary to control two people. One person can control two people with the right words, weapon and tools."
Brown said an important clue in the cases is that in some of them, the driver's window had been rolled down.
"This would indicate someone approached the vehicle and was likely thought to be a police officer," she said. "It would seem, considering the cars were pulled off the road in isolated places and the victims were in various stages of undress, that the killer liked to pull up to cars he believed had couples in them, involved in some manner of lovemaking."
Since rape does not appear to be a motive, Brown said she believes the perpetrator wanted to "teach the couples a lesson."
"Most likely, the killer was jealous of their activities," she said. "The couples were killed because they were having too much fun, and the murderer put a stop to it. This kind of ideation, this anger toward the trysts of lovers, the lack of robbery or rape, indicates that the crimes were more likely committed by one person with a very specific focus. If two [killers] were involved, the other individual would likely offer more criminal expressions than simply eliminating the couple."
Brown said the perpetrator could be involved in law enforcement or, more likely, "wished he were."
"He wanted authority and probably did not have it," she said. "His crimes gave him this feeling: He was able to surprise, control and punish 'wrongdoers.'"
The only one of the other Virginia killings Brown finds potentially related is the Shenandoah Park case, because it involved "an individual noting two persons engaging in a physical relationship and moving in to stop the action."
Holding Out Hope, Together
It has been 20 years since the last Colonial Parkway murders. The renewed investigative push, aided by advances in DNA, may finally bring some answers. But Special Agent Turner said it will take at least six months for his office to get the results of the materials it is having tested -- and even then, the mysteries may remain unsolved. And so the wait continues.
Meanwhile, Joyce Call-Canada said her hopes aren't pinned on new technology but on an old-fashioned bout of morals.
"My hope is that someday, somebody will get a conscience," she said. "Somebody has to know something. If it is not the person who did it, then somebody that knows that person and knows they did it."
In their shared losses, the families of the victims have been forever bonded. With the renewed investigation, they have been reunited again.
"The [victims'] families have been brought back together again," said Janette Santiago. "Unfortunately, the murders are the reason, but we are together, and we are all united in hope. Even if we can get just one case solved, it would be a great victory for all of us."