Pam Isbell talked to her brother Michael “Mike” Scott on the phone nearly every day. She lives in Spartanburg, South Carolina and he lived about an hour away in Pendleton, so they often caught up while she drove to the school where she was a teacher.

“My brother was my everything. He was the constant in my life,” Pam told Dateline. “He always checked in on me and my girls. He was like the caretaker of the family, and the community.”

Halloween weekend arrived. Along with college football season. Pam is a Clemson fan, but Mike’s favorite team was the South Carolina Gamecocks.

“He called me that evening… I think it was a Saturday night. Around 9, 9:30,” Pam said. “My team had just won a game. He called me to congratulate my Tigers.”

That was October 31, 2015 — the last time Pam spoke to her brother.

Two days later, on Monday, November 2, Pam’s brother Mike, 58, their mother, Barbara Scott, 80, Mike’s wife Cathy, 60, and Cathy’s mother, Violet Taylor, 85, were all found dead at their home on Refuge Road in Pendleton.

The day had started out as a normal Monday for Pam as she drove to work and attempted to call her brother. But this time he didn’t answer. Pam told Dateline her workday was especially busy that day and it wasn’t until she arrived back at her house late in the afternoon that she got the call that would shatter her world.

“They were gone. Dead. All of them,” Pam said. “My brother. My mother. My sister-in-law. Her mother. Just gone.”

Authorities with the Anderson County Sheriff’s Office told NBC affiliate WYFF back in 2015 that the murders, soon known as the Pendleton quadruple homicide, were some of the most violent they had ever seen.

"This was very violent. Very violent deaths on all four of them," Anderson County coroner Greg Shore told WYFF.

According to Anderson County authorities, Cathy’s daughter, Amy Vilardi, found the bodies. Amy told WYFF that she went to check on her mother when she realized she hadn’t seen her out walking the dog.

"When I went to knock on the back door, the door just pushed open so I walked in and it was dark and I just flipped the light on and there they were. They were just, they were there," Amy told WYFF.

There was no sign of forced entry in the home, Shore told the station, and the daughter told authorities the back door was open.

"She said that was very unusual. Usually they keep the house locked down, even when they're at home," Shore said. "I do believe that the person involved was welcomed in or came in, and that's when the homicides took place."

Three of the victims were found in the den, and one was found in the bedroom, according to authorities. Each victim had at least one gunshot wound.

Shore told WYFF the bodies were on the floor, but the house was not disturbed, “other than the area where the victims were laying.”

"I don't understand why any of it has happened and I just keep thinking it's a dream I'm going to wake up from," Amy told detectives in 2015, according to WYFF.

At the time, Amy and her husband, Ross, lived in a separate home on the property where the murders took place, Pam told Dateline. They ran a pet grooming business out of their home and their children spent much of their time with their grandparents and great-grandmothers at the Scott residence nearby.

Authorities told Dateline they believe the murders took place sometime after 1 p.m. on Sunday, November 1. Mike, who was a state employee with the South Carolina Department of Transportation had taken a few days off work, but texted his boss at 1 p.m. on Sunday, to let him know he’d be returning to work on Monday.

A relative who Pam said often visited the Scott residence on Sundays told police he stopped by around 3 p.m., but he said it appeared that no one was home.

All four of the victims had lived together in the house on Refuge Road for several years, Pam told Dateline.

Mike and Cathy were married just nine years before they were murdered. They met when they were very young and became junior high school sweethearts, Pam said. But after Cathy transferred to a private school, decades passed before they were reunited.

Pam told Dateline that Mike and their mother, Barbara, and Cathy’s mother, Violet Taylor, eventually moved into the house with them. Cathy worked at Ryan’s restaurant for years before retiring, and eventually stayed home to care for their ailing mothers, along with some of their grandchildren.

“They spent their entire married life together caring for ailing mothers and grandchildren,” Pam said. “But they loved taking care of their family.”

Family members said they just want answers and justice for their loved ones.

Tammy White is Violet’s granddaughter and Cathy’s niece. She told Dateline the murders were horrific for the entire family, but that they try to be there for each other.

“We’re a close-knit family and we’re just trying to help each other out,” Tammy said. “I know I’m glad I have my family to help me get through it. It’s been so hard on everyone.”

Tammy, who also lives in Pendleton, told Dateline she grew up being very close to her aunt and grandma.

“My Aunt Cathy and I went on a cruise when I was younger, and she’d always take me shopping and we’d explore flea markets,” Tammy said. “Of course, as we got older, I was working a lot, and I didn’t get to see her as much. But we tried to get together during the holidays. Now, holidays are never the same.”

Tammy, who lives in Pendleton, works as a prudential analyst at a hospital, and is married with a young daughter.

“We all would love for this to be solved soon. For it to be over,” Tammy said. “Not just an arrest in the case, but they need to be prosecuted. We need justice.”

No arrests have been made, but Sgt. J.T. Foster with the Anderson County Sheriff’s Office told Dateline the department is hoping to be able to solve the Pendleton quadruple homicide case soon.

“We have found pieces of evidence that were sent to several different labs,” Sgt. Foster said. “The findings of that have led us to other labs and we are still waiting on those results.”

Sergeant Foster said the results from the labs could be the missing link to an arrest in the case.

If you have any information about the murder of this family, call the Anderson County Sheriff’s Office at (864) 260-4400 or call the Anderson Area Crime Stoppers at 1-888-CRIME-SC. Callers can remain anonymous and may be eligible for a cash reward if their information leads to an arrest and conviction.