It’s been 35 years since Suanne Burt Sardi last spoke with her older sister, Sandra.

Thirty-five years since the two women hung up the phone on an early morning in January, promising to check in again in the afternoon.

Thirty-five years since 41-year-old Sandra Burt Carrera was found shot to death in her Arlington, Virginia, home.

And for 35 years, the tragedy has gone unsolved.

Suanne was only 25 years old on January 15, 1991, when she received a phone call from her 11-year-old nephew, Alex Carrera. “He said, ‘Aunt Suanne, my mother’s dead. She’s shot in the head,’” Suanne told Dateline. “It just seemed inconceivable.”

And it was. Just hours earlier, Sandra had been alive and well. The sisters had been catching up on the phone. Sandra was living in Arlington, Virginia, where she worked in marketing for HOK Architecture. “She loved living in D.C.,” Suanne recalled. “She just thought it was so exciting.”

“She was very warm, she was very funny, and bright,” Suanne said. Sandra was 16 years older than Suanne and “was kind of like a second mom” to her. She was dedicated to her work, carving out her place in the architecture industry — first in Pittsburgh, and then in Washington, D.C. But according to Suanne, “her number one job was mom” to her son, Alex.

Sandra moved to Arlington following her divorce from Alex’s father. According to Suanne, the divorce had been amicable, and Sandra had started dating again.

On the morning of January 15, Sandra and Suanne spoke on the phone. Sandra told Suanne that the man she was seeing had come over the night before, but had already left before they got on the phone. They talked for a bit before Suanne had to hang up. “I remember the last thing I said was, ‘I have to go, I have to get to econ class.’ And she said, ‘OK, I’ll call you later.’” The sisters made plans to talk again in the afternoon around 2:00 p.m., and then said their goodbyes.

The afternoon came and went. Suanne, who was earning her MBA at the University of Pittsburgh, was having friends over that night. “I never thought about the fact that she didn’t call me,” Suanne said. “And then at six o’clock that night, Alex called me.”

According to Suanne, Alex forgot his keys to the house when he went to school that day, so he went to play with a neighbor after school. Around 6:00 p.m., he noticed the lights were on at his house, so he headed home. The front door was unlocked, and when he went in, he saw his mother’s body. Alex called 911, and shortly after that, called Suanne and his father, who lived in Pittsburgh, to tell them what had happened. “Absolutely horrific,” Suanne said. “It still makes me shake, thinking about all of it, all these years later.”

The Arlington County Police Department reported to the scene and continues to be the primary investigating agency. Media Relations and Public Affairs Manager Ashley Savage provided a response to Dateline’s questions regarding Sandra’s case via email.

According to Savage, the Arlington County Police Department arrived at the scene at approximately 6:09 p.m., where Sandra was found “fully clothed, laying on her side at the bottom of a short flight of stairs.” The manner of death was ruled homicide, and the cause of death was a gunshot wound.

According to Suanne, Sandra had been shot “execution-style” three times in the head. “She was blown out of her shoes and off the landing, onto the floor down below,” she said. “It’s absolutely just brutal.”

According to Arlington County PD, Sandra’s “home is not believed to have been disturbed.” Nor do they believe anything was taken from the home.

Suanne says that when she was on the phone with her sister earlier in the day, Sandra told her she was going to run errands on the way home from dropping Alex off at school, stopping for cash and to get groceries. “The groceries were sitting on the dining room table, and the cash was on the steps, totally undisturbed,” Suanne said.

“Her home was processed, and various personal items and forensic evidence were collected,” Savage wrote Dateline. “Various evidence has been tested throughout the years but has not led to the identity of a suspect.”

The weapon used to kill Sandra has not been located. “During the course of this investigation, detectives conducted a comprehensive investigation into Sandra’s life with the goal of identifying the individual(s) responsible for her death,” Savage wrote. “Despite these efforts, no arrest has been made in her case.”

Suanne summed it up: “The biggest problems were there were no witnesses, there’s no clear motive, and they never had a weapon.” The investigation stalled.

Over the last 35 years, the Arlington County Police Department has led the investigation into Sandra’s murder, receiving help from various agencies, including the FBI. “As this is an open investigation, additional details regarding their assistance is not releasable to ensure the integrity of the open investigation,” Savage wrote.

“The passage of time does not diminish the need for answers and accountability in this senseless act of violence that took Sandra’s life,” Savage wrote. “Anyone who knew Sandra or who lived in the area of Windgate Townhomes in Arlington, VA on January 15, 1991, is encouraged to reach out to the Arlington County Police Department. Detectives continue to follow-up on investigative leads in this case and remind the public that any information, regardless of how small it may seem, could be the tip that leads to justice on behalf of Sandra and her family.”

In the years since Sandra’s death, the family has faced the immense grief that comes with such a violent loss. “We were really, really close,” Suanne said. “We were best friends.”

As this year marks the 35th anniversary of Sandra’s death, Suanne “feels a sense of urgency” to find answers. In her sixties now, she longs for justice to be served in her sister’s case, and looks forward to what a fresh look could mean for Sandra’s story.

If you have information about Sandra’s case, please contact the Arlington County Police Department’s Homicide/Robbery Unit at 703-228-4180 or ACPDTipline@arlingtonva.us. Information may also be reported anonymously through the Arlington County Crime Solvers hotline at 1-866-411-TIPS (8477).

If you have a story to share with Dateline, please submit it here.

BLACKSBURG, Va. – For many athletes, ACL-related injuries can put them out of a sport for long periods of time. Olympian Lindsey Vonn isn’t letting that happen – but how?

Vonn crashed while training for the 2026 Winter Olympics on Jan. 30 and ruptured her ACL. Robin Queen, a Virginia Tech professor of biomedical engineering, explained why exactly the ACL is so important, even in a sport like skiing.

“The ACL is particularly important for stabilization when someone is pivoting or twisting and when they are landing from a jump or out of the air.”

Robin Queen, a Virginia Tech professor of biomedical engineering

Queen also stated that this is a rare occurrence to see an athlete back on their feet this quickly following such an injury. She emphasized that, when athletes do continue in a sport prior to their ACL being reconstructed, they will wear a knee brace. Many athletes also have better body awareness, which can help with stabilization.

“It is important to understand that there is a mental aspect to her being able to ski, and ski well. Often following an ACL rupture, there is a greater fear of movement and a fear of reinjury, so she will be managing the typical physical and mental demands of competing at an elite level while also potentially worrying about the stability of her knee and how it will feel while she is competing.”

Robin Queen, a Virginia Tech professor of biomedical engineering

You can read the full write-up from Virginia Tech here.