Primetime Crime: Savagely Killed in Their Own Home

Aug. 2, 2007 — -- Alan and Diane Johnson seemed to have a picture-perfect life.

The longtime sweethearts, who had been together for 20 years, lived in a beautiful home on the outskirts of Sun Valley, Idaho. Alan was part owner of a landscaping company and Diane worked at a medical clinic. They treasured their family, which included two children, 22-year-old Matt and 16-year-old Sarah.

But just after Labor Day weekend in 2003, that happy family life abruptly came to an end — Alan and Diane were brutally executed in the bedroom of their home.

Watch this full story in the series "Primetime Crime" Tuesday at 9 p.m. EDT

For investigators, the first clues in the shocking case came when they discovered that 16-year-old Sarah had fallen in love with an illegal Mexican immigrant. Alan and Diane did not approve of her relationship with Bruno Santos, a 19-year-old high school dropout from a poor home across town.

Santos became the source of heated family arguments and relatives and friends feared that the relationship was tearing the once close-knit family apart. Syringa Stark, one of Sarah's friends, said, "I felt she could do a lot better. He was a high school dropout and was selling drugs and she was from a nice family. It just didn't seem like it was right."

Tensions mounted the Saturday of Labor Day weekend 2003, when Diane and Alan discovered Sarah was sleeping over at Santos' apartment. When Alan picked up Sarah, he told Santos that he was to stay away from his daughter. He even threatened to report him to the police for having sex with an underage girl.

But that would never happen. Tuesday morning, Alan and Diane Johnson were killed.

Blaine County Sheriff Walt Femling said it was the most disturbing crime scene he had ever seen. "There was blood and hair on the carpet. It was on the ceiling. It was on all the walls. There was part of a skull cap in the hallway."

Femling immediately closed down the street and in doing so stopped a garbage truck that had just made its rounds. The garbage truck turned out to contain the key evidence in case: a bloody bathrobe, a left-handed leather glove and a right-handed latex glove … all containing someone's DNA.