Reporter: Shirley seitz dead and gone at age 59, the fifth wife of dr. Michael wohlschlaeger. Her family, convinced he had something to do with her sudden, unexplained death, searches his long trail... See More
Reporter: Shirley seitz dead and gone at age 59, the fifth wife of dr. Michael wohlschlaeger. Her family, convinced he had something to do with her sudden, unexplained death, searches his long trail of matrimony and comes across the odd tale of wife number one. Her name was lynn. I said, I need to tell you some things that I've found out about michael. Reporter: The family had discovered what is to them a very strange coincidence. Shirley's daughter sharon arranged to meet her uncle to tell him about it. I knew that it would be upsetting, so I had just asked ricky, let's just ride up to the cemetery. Reporter: They come here, to of all places, the hike rock cemetery, where they had buried shirley less than two weeks before. Right beside shirley's grave -- Reporter: Among the shad dopes of the tombstones, it's an oddly comforting place, where they can feel shirley's presence, and where sharon can broach a difficult subject, with the one family member still close to mike. She shows ricky an old, yellowing newspaper article. A brief story about the sudden death of a young woman in gainesville, florida, in 1977. Lynn wohlschlaeger, mike's first wife. The article says, "a 25-year-old woman apparently choked to death friday on a throat lozenge." Choked to death on a cepacol lozenge, that's what her death certificate says. It appears there was no police investigation. Sharon and the rest of the thomas family say they find two things strange about that. First, an otherwise healthy 25-year-old woman choking to death on a cough drop. Second, they say michael had always told them a different story. He told them his first wife didn't die suddenly. She died a slow, painful death from cancer. Michael had told us the entire time that he was married to mama that lynn had leukemia. Reporter: And that's how she died? Yes, that's how she died. And that when she died, he was holding her hand, consoling her in the bed. Reporter: He never mentioned a throat lozenge? No. It may me wonder, well, what else has he lied about? Reporter: What else has he lied about? For the answer to that question, we take you to chipley, florida, and a suspicious fire in dr. Mike's past. Nearly 20 years ago. I was approaching this place of business here. I detected smoke, seen smoke. Reporter: Lieutenant tillman mears, in plain clothes now, was a rookie patrolman back in the day. He says dr. Michael, as everyone called him, was the go-to chiropractor in town, especially for female patients. One night, his office caught fire. The doctor was found standing across the street, just watching it burn. My first question was, why didn't the doctor call the fire department? Reporter: Instead, he tells an incredible story. Someone trying to kill him set the fire while he was trapped inside. He said he woke up smelling smoke and had to fight his way out of the burning building. Reporter: Escaping by karate kicking through a burning wall, barefoot. But when police check his feet, there's no burns. Not even a scratch. Mears says the skillful chiropractor was twisting the truth. He thought I was going to go away, I think, and believe what he said. Reporter: But the cops say dr. Mike's story stunk. And so did he. Once I approached mr. Wohlschlaeger, I detected a smell of diesel fuel on his person. Reporter: And that was before they found the can of diesel fuel and a match. And the suspected motive. He was flat broke and after the insurance. Dr. Wohlschlaeger was arrested, tried and convicted of arson. One thing stayed with the policeman all these years -- he says dr. Mike threatened him. After the jury came back with a guilty verdict, he turned and told me that I'd pay for this. Reporter: Dr. Mike was the one who paid, although he got no prison time, just 15 years probation. And with a surrender of his license, it was the end of his career as a sky practice or the. But for shirley's family, it was evidence of much more. Dr. Mike, when he is broke, they say, is not above committing a crime or inventing aer of a story to cover his tracks. Who had the motive? Who had the opportunity? Who has lied in the past? Reporter: Trying to answer that question, we contacted mike's second wife, paula. She says he never harmed her. Even so, as you've seen, he's no choirboy. In fact, he's a convicted criminal. But capable of killing? Who says? She does. Other ex-wives are now coming out of the woodwork with startling stories of their own. All of a sudden? Bam to the back of the head.
This transcript has been automatically generated and may not be 100% accurate.