ST. CLOUD - It's been nearly 42 years since Susanne and Mary Reker went missing in St. Cloud. They were found nearly a month later murdered in Quarry Park, both were stabbed multiple times.

Authorities still haven't determined who murdered the girls, but signs indicate they're getting closer with the suspects they're looking into. They could be a few witness accounts away from a breakthrough in the case.

Someone just needs to step forward with the last crucial bits of information they need.

"Somebody knows something that they're either hiding on purpose or are just afraid to say what they knew at the time," Stearns County Chief Deputy Bruce Bechtold says.

"There are people out there who have never come forward that know what happened, know who did it and are not telling what they know. People who have never come forward before," Rita Reker, the mother of the two girls, says.

It was Labor Day: September 2nd, 1974, when Mary (15-years-old) and Susanne (12-years-old) left home around 11:00 a.m. to go shopping at the nearby Zayre Discount Store (now currently home to Save-a-Lot Grocery and Liquor). Rita recalls it being a beautiful summer day after a big family reunion the day before.

"I didn't want them to go very badly but they needed some school supplies. They were going to be back quickly."

Photo: Tri County Crime Stoppers (Left: Susanne, Right: Mary)

They were last seen at the store at 1:30 p.m. When they didn’t come home for dinner, their parents contacted police. It started a search for the girls that lasted 26 days.

"I remember fixing supper that evening and we generally ate around 5 o'clock and when they weren't there we knew something was wrong."

The search quickly became nationwide in scope. Old WJON files say bulletins and photographs of the girls were sent to all major cities in five upper midwest states and to every state crime bureau. Mary was wearing green wire rim glasses, a green army fatigue shirt with "Reker" on the front pockets and blue jeans. Susanne was wearing gold wire rimmed glasses, a white cotton short jacket and blue corduroy jeans.

The search for the sisters concluded at a rock quarry. (Stearns History Museum; Myron Hall Collection)

On September 28th, two teenagers who were walking on the edge of a rock quarry on the western outskirts of town, found Susanne in the tall grass nearby at about 2:00 p.m. She was stabbed 13 times.

Mary was found unclothed 40 feet below the surface of the water. She had been stabbed six times and her clothes had been thrown into the quarry after her. Her body was recovered by divers at about 6:00 p.m.

The murders shook the community. To this day: Rita still can’t comprehend why such a horrible thing happened to her daughters.

"Mary had planned to become a teacher when she got older and Susanne planned to become a doctor and she was a violinist. They had hopes and dreams for themselves and somebody just chose to kill them."

What Are Authorities Looking For?

After talking with the Stearns County Sheriff's Office, Rita and looking through old WJON files, here's the common threads we've found for who may be responsible:

Both the Sheriff's Office and Rita believe the suspect is a man who's likely from the St. Cloud area.

Rita thinks the man had an accomplice. The Sheriff's Office can't confirm this, but Bechtold says they aren't ruling out the possibility.

Profilers in the case believe the person was young at the time of the murder.

Bechtold confirmed that some of the suspect(s) they are looking at are still alive.

Bechtold says it's possible they haven't heard from a key witness because they felt what they saw "wasn't important". The Sheriff's Department urges anyone who saw something to contact them.

Perhaps the most mysterious part of the case is a page from Mary's diary that investigators found. It seems to show that she had reason to fear for her life. It reads:

"Should I die, I ask that my stuffed animals be given to [my sister] and if I am murdered, see that justice wins over. I have a few reasons to fear for my life. What I ask is important."

Bechtold confirms the diary entry is still a big piece in their investigation.

"It's pretty significant to look at that, you certainly can't rule that out because what 15-year-old girl writes that?"

Authorities seem content with the physical evidence they have for the investigation. The missing pieces are witness accounts from a crucial time: after the girls were at the Zayre store.

"We'd like to know what happened from the time they left the store until they were murdered: if [someone] saw certain people together...and I can't say who those certain people would be, but we have witnesses who saw the girls at the store, we have witnesses who saw them in different places." Bechtold says.

Authorities still have the girls clothing and there's the possibility they could bring the items back for further DNA testing if scientific advancements in the field are made. DNA testing on the clothes in 2006 revealed no clues.

Another interesting development with the case happened in 2005, when it was presented to the Vidocq Society: a members only crime solving club of detectives, FBI agents, psychologists and scientists who hear cold cases in Philadelphia. After hearing this case: they confirmed to the Sheriff’s Office that they were on the right track.

"Their opinion at the time that we presented it to them is that the person or persons we are looking at, look like they would be viable suspects," Bechtold says.

Old WJON Radio copy for the Reker case from the 70's and 80's

Rita says this helped confirm in her mind who was responsible. She isn't able to comment on names.

"That was a breakthrough for us."

A new investigator was also assigned to the case recently. Bechtold says John Niemi has been with the department for about 10 years. He met with Rita in Mid-July to keep her informed on what they were doing to try and solve the case. The Sheriff's Office hopes he will give them a fresh perspective.

In 2013, Fred Reker, the girls father, died at the age of 84. Rita is now 80-years-old but still hasn’t given up on finding closure.

"We had four other children and they had to grow up with the mystery of this: that was hard for them. Our family bares the scars of this yet and I guess before I die I'd like to see it solved."

If you know something (especially if you saw the girls after they went to the Zayre store), you should contact the Stearns County Sheriff’s Office at 320-251-4240 or the Minnesota Bureau of Criminal Apprehension, Cold Case Homicide Unit at 1-888-234-3692

There's still a reward of up to $50,000 being offered for information on the murders.

Videographer Alex Svejkovsky contributed to this story. Thanks to the Stearns History Museum for photos in this story and video.