Suspicion surrounds Rebecca Schwartz long after her wealthy husband's death

While Rebecca Schwartz has not been criminally charged in the case, a jury in civil court found her liable for intentionally killing or participating in her husband Steven's death.

For John Diebel, she’s the suspect who got away.

Diebel, a retired detective, spent more than a decade investigating the brutal murder of Steven Schwartz, a wealthy doctor whose 2014 death shook Florida’s Gulf coast. In his first interview about the case, Diebel recalled that the investigation was one of the most extensive of his nearly 50 years in law enforcement — one filled with unexpected turns and dead ends that led detectives far from the doctor’s sprawling mansion northeast of Tampa.

Retired detective John Diebel spent more than a decade investigating the death of Steven Schwartz.DatelineYet in the end, Diebel’s investigation for the Tarpon Springs Police Department produced a single conviction for a crime far less serious than murder. And it did not yield criminal charges for a person who Diebel believes is responsible for the killing: Schwartz’s wife, Rebecca Schwartz.

“It’s like the one case where you didn’t get the suspect that you knew in your heart that she committed a murder,” Diebel told “Dateline.” “You just didn’t have enough for the state attorney’s office to go forward with prosecution.”

DATELINE FRIDAY SNEAK PEEK: The Death of Dr. Schwartz01:55While Rebecca, 65, has never been criminally charged in the case, a jury in civil court — where the standard of evidence is lower than in criminal proceedings — found her liable this year for intentionally killing her husband or participating in his death. That decision, made in response to a wrongful death lawsuit filed by Steven’s family, included a judgment that required Rebecca to pay the doctor’s family nearly $200 million in damages.