Murder Mystery: Tragedy or Poisoning?

April 5, 2007 — -- Cindy Sommer spends her days in a San Diego jail cell -- the last place she says she belongs -- convicted of poisoning her husband and watching him die.

Her husband, Marine Sgt. Todd Sommer, was the father of Cindy's youngest child, and her three children from a previous marriage also called him Dad. Cindy was arrested and charged with Todd's murder in November 2005, but she insists that she did not kill her husband. She's had few chances to see her children since her arrest.

She was convicted of murdering Todd in January and now awaits sentencing.

In 2002, just before Valentine's Day, Todd Sommer died suddenly in his home at Marine Corps Air Station Miramar in San Diego. He was 23 years old at the time of his death. Doctors at the hospital told Cindy that Todd had died of cardiac arrhythmia, and while he'd been experiencing flulike symptoms, just two weeks before he died he had passed his Marine physical in perfect shape.

Before Todd's death, most who knew the couple thought Cindy and Todd were very much in love. They'd met through friends in 1999, and they married soon after Cindy's divorce.

"I loved my husband. I did everything that I could for him," said Cindy. "He was my life. And our family was my life."

But according to Cindy's close friends, who spoke exclusively to "20/20," there was also a less wholesome side to Cindy and Todd's relationship. A few friends had intimate knowledge of Cindy's life, much of which would eventually be used against her during the trial.

Dana Benton said that she'd been invited to participate in a threesome with the couple.

"She came to me one day and said Todd thought that I was pretty, and wanted to know if I wanted to join in with them," Benton said. "But I told them that I'm not like that. So I turned it down."

After Todd's funeral, friends and family gathered at Cindy's house to mourn Todd's death. Mourning led to drinking, and later that night, Cindy and her friends left the somber gathering and headed to a strip club. Cindy's friends found her actions to be unusual but decided not to question them.

"I thought it was weird, but that's what she wanted to do, and some people take out their sadness differently," one of her friends said.