MUSKEGON COUNTY, Mich. -- One year into the unsolved murder of Rebekah 'Becky' Bletsch, investigators are starting back at the beginning.

The 36-year-old mother was shot in the head multiple times and left for dead along rural Automobile Road in Dalton Township on June 29, 2014. She was jogging a familiar stretch of road early that Sunday evening, less than a mile from her home, when she was shot.

Police said none of her valuables were taken.

That evening, a couple driving down the rural road spotted her laying face down on the ground. They called 911.

“We come up to this lady," the caller said in 911 tapes released to the media in January. "She’s laying in the road. I think she was hit by a car. She got a head injury.”

Det./Lt. Jim Christiansen, with the Muskegon County Sheriff's Office, said no stone is being left unturned in the unsolved case as investigators work their way back to the beginning to re-visit old leads and police notes.

"We're definitely working on it, we're working on it pretty much every day where somebody is looking at stuff," he told FOX 17. "It can still be solved, and we're hopeful that it will be."

Christiansen said the case file on Bletsch has grown substantially in the past year, with enough paperwork and reports to fill an entire paper ream box. Currently, people are being re-interviewed about information authorities may not have had during initial interviews, he said.

There is at least one full-time investigator working the case daily, according to Christiansen. At one point, he said there were as many as 15 detectives from several different agencies ranging from the county sheriff's office to the FBI working the investigation.

Christiansen said the importance of the case hasn't diminished.

"The people who are working on it, most are people who were working on it from the beginning, they have a vested interest in it too," he said.

Family and friends of Becky gathered Saturday at the Dalton Township home where she once lived to mark the anniversary of her death. Becky's husband, Kevin, and daughter, Ellie, still live in the home, just down the road from the where she was killed.

“Becky always got together with everybody," said Nicole Winberg, Becky's sister. "This is what they did, this is how they spent their time with friends and family and it was a way for us to remember her."

Amid the backdrop of a sunny afternoon and the muddled sound of laughter and conversation among those visiting Saturday, Winberg said a heavy weight still hangs over the home where she once could always count on seeing her sister.

“She held us all together and I don’t think you really realize that til you’re gone… It has changed our lives in a way I can’t even explain," said Jessica Josephson, Becky's other sister.

“Not having her here to do those things is hard, she’s everywhere here."

Just adjacent to the rear of the Bletsch home stands a wooden memorial Kevin constructed in the months following her death. Flowers from her funeral once filled the space underneath. Above it, a sign reads 'In loving memory, Becky Bletsch' which is emblazoned on a Harley Davidson-shaped badge. Becky and her husband were avid bikers.

Both Jessica and Nicole stood in silence for a time Saturday afternoon beside the memorial. Tears traded off and on for moments of laughter as the two recalled stories of Becky and the time they used to spend with each other at the house.

Becky's family hasn't been shy about their wavering faith in the investigators working the case. In January her sisters and husband expressed their growing frustration in what they alleged was a lack of communication from police on the status of the investigation.

Kevin Bletsch, Becky's husband, who has not yet granted an on-camera interview to any media, told FOX 17 in January he believed police had been sloppy with evidence at the scene early on in the investigation. Police said Kevin was out of town with the couple's daughter the day Becky was killed.

“I think they’re in way over their heads,” he said off camera. “There have been bobbles along the way right from the beginning.”

In the time since, relatives said investigators have been slightly more forthcoming with updates. Josephson told FOX 17 it's reassuring to hear police are now re-evaluating old leads and notes.

Visiting the site on Monday where her sister was killed one year prior Josephson paid her respects and left flowers. She said it was the first time she had been back to the site since the accident.

"It's hard to look around, knowing that this was the last place she was," she said, pointing out the still-visible circles spray painted on the pavement where investigators had incidentally found shell casings the day Becky was murdered.

"In your mind you think, what happened? Did somebody come out of the woods, did a car pull up on her? A million things go through your mind."

Josephson said she was touched to see others had already placed mementos at the site before she arrived, adding she and her sister are not ready to give up on finding justice for Becky.

“I will take every opportunity I can to keep my sister’s name out there, to beg people to tell me who did this," she said.

Police say anyone with information about the case, or who might've seen anything suspicious in the area, should call the Detective Bureau with the Muskegon County Sheriff's Office at 231-724-6658 or Muskegon County Silent Observer at 231-72-CRIME.

Family friends of the Bletsch's have also paid to put up several billboards across the Muskegon County area in hopes of generating tips in the case. Family is also offering a $10,000 reward for any information that could lead to an arrest.