For 16 years, Susan Shaw's family and friends insisted she did not take her own life when she was found slumped and unconscious inside an exhaust-filled garage at her James Island home.

They pointed to her reputation as a bright, hard-working young nurse. They noted that her widowed husband, a state trooper, refused to answer investigators' questions after her 1998 death. Things didn't add up, they said, and they pleaded for someone to reconsider the finding of "suicide" listed on her death certificate.

That day has finally arrived.

After a six-month review of the case, Charleston County Coroner Rae Wooten said she is changing the official ruling on Shaw's manner of death to "undetermined."

Wooten, who was not coroner when Shaw died, said she doesn't have the evidence to conclusively say it was a homicide, but she has strong doubts that the 26-year-old woman killed herself.

Wooten said the initial investigation appeared to have been compromised, and subsequent developments in Shaw's husband's life - including his fatal shooting by police in Arizona - raised new doubts about the 1998 ruling. She began reviewing the case after The Post and Courier raised questions about the findings in a May 2013 article.

"The more I learned about her, there was nothing that said this young lady planned to take her own life," Wooten said. "There is enough there that I believe to leave it as a suicide would be wrong."

Charleston County sheriff's Maj. Eric Watson said the coroner's ruling will prompt a review of the case by his agency's investigators as well.

Shaw's father, Tom Beacham of Greer, said Wooten's decision has brought relief and some sense of closure to his family. She called him with the news on March 7, the anniversary of his daughter's death.

"It made me feel a whole lot better," Beacham said. "I never did believe that Susan committed suicide. I told them that from the start, but no one back then would believe me."

Susan's husband, Highway Patrol trooper Bill Shaw, was hovering over her body when emergency crews arrived at their Trapier Drive home 16 years ago. He told them he had found her unresponsive in the driver's seat of her idling Chevy Tahoe inside their garage when he came home for lunch. She had stopped breathing, and burns from the overheated vehicle covered nearly all of her body. She quickly died.

Tests revealed that Susan Shaw succumbed to carbon monoxide poisoning. She had been drinking wine on top of antidepressants, and authorities learned that she had been troubled by problems in her six-year marriage.

With this in mind, her death was quickly ruled a suicide.

Doubts arise

But family and friends didn't buy that conclusion. Susan Shaw hadn't left a suicide note, and friends saw no indication that she would harm herself.

They described Bill Shaw as a hard-partying, cash-strapped man who disappeared on weekend trips without explanation and was carrying on a relationship with an Arizona woman whom he had met online, according to a State Law Enforcement Division report.

Just seven hours before her death, Susan Shaw met up with a state trooper who was a friend of her husband and said that she "was going to go home and tell Bill he would have to leave," according to a SLED report.

Emergency workers described Bill Shaw as distraught when they arrived at the couple's home that day, and found him on the back porch giving his unconscious wife CPR.

Detectives found it suspicious that he had left a message for Charleston criminal defense lawyer Andy Savage at 10 a.m. that day - three hours before Susan's body was found. They also noted that someone using the Shaws' home phone had called their voice mail at 1:01 p.m. - before calling 911 - while Susan lay unconscious in the garage.

The Beachams said Shaw started inquiring about Susan's $130,000 life insurance policy just days after her death, but he repeatedly rebuffed attempts by Charleston County sheriff's investigators to get a written statement from him about the incident in the weeks and months that followed.

He quit his job in October of that year and moved to Arizona, where he died in March 2013. Phoenix police officers shot him on St. Patrick's Day after he trained a laser-equipped pistol on them at his apartment, police said. Police had been called there to check out a report that Shaw, 46, was fighting with his latest wife and breaking things.

New conclusions

Wooten said she spoke to Phoenix authorities and a variety of people who had known Bill Shaw. She came away with the impression of a self-centered man with a capacity for violence and a lack of concern about the consequences of his actions. That, coupled with the facts of the 1998 case and what she had learned about Susan Shaw's behavior, made her uneasy about the suicide ruling, she said.

Wooten said the lack of a "pristine crime scene" and the loss of some potential evidence also troubled her.

Wine glasses at the Shaw home, for instance, hadn't been preserved after Susan's death, so investigators couldn't test to see if someone had spiked her drink with the anti-depressant. And authorities had allowed Shaw's attorney, Savage, to take the Tahoe in which she was found to a detailing shop that same day, wiping the vehicle clean of whatever evidence lay inside, records show.

Savage declined to comment on the case and Wooten's decision when contacted this week.

Wooten said she would be open to looking further into the case if new evidence emerged, but for now the best solution seemed to be changing the manner of death to undetermined.

"I don't, at this point, have the cold, hard facts I feel I would need to move it to 'homicide,'?" she said.

Beacham, 81, said he can live with that. The stain on his daughter's name is now gone, and there would be no one left to prosecute even if authorities did find his former son-in-law culpable in Susan's death.

"He's dead," he said. "He already got his sentence."

John Burnett, who worked on the case as an investigator with the 9th Circuit Solicitor's Office and later as a SLED agent, said he was pleased to see Susan Shaw's parents get some relief after so many years of fighting to prove that she didn't kill herself.

"In my heart of hearts, I always believed that guy killed her," said Burnett, now retired. "There was just no way we could prove that."

Reach Glenn Smith at 937-5556 or Twitter.com/glennsmith5.