Preview: A Case for Murder

A Young Man's Stabbing Death Sparks An International Debate

(CBS)  The last time anyone saw Hugues de la Plaza alive, he was saying goodbye to friends at a San Francisco club after celebrating a recent promotion, in the summer of 2007. The next morning, police found de la Plaza dead in his apartment - stabbed in the neck, chest and stomach. Two years later, family and friends remain consumed by a fight to find the truth.

De la Plaza was a young, handsome sound engineer, living in San Francisco. Armed with good looks and his French accent, he was known to friends as a "ladies' man." He was well-liked, successful and full of life, all begging the question - what happened the night of his death?

The crime scene was a collection of contradictions. De la Plaza’s apartment was covered in blood, with bloody handprints on the walls, drops of blood leading into and out of the kitchen and on his front porch. It seemed to have all the characteristics of a homicide, except there was no sign of a struggle, or of anyone else's DNA in the apartment. Also, nearby security cameras failed to capture any image of an assailant. De la Plaza’s death was classified by the San Francisco Medical Examiner’s office as “undetermined,” which raised the possibility of suicide. But there was one problem with that theory - there was no bloody weapon found in his apartment.

Half a world away, living in France, de la Plaza’s parents, Francois and Mireille, were devastated by the sudden loss of their only child and frustrated by the San Francisco Police Department’s investigation. At the request of Francois de la Plaza, French authorities were called in under a rarely used treaty to conduct their own investigation, and made a remarkable discovery - unknown DNA on Hugue de la Plaza's watchband. In their 2,000-page report, French investigators outlined a simple conclusion: homicide. And in another shocking twist, it was revealed that the San Francisco Police Department had commissioned an outside review of the case by an independent medical examiner.

"48 Hours Mystery" obtained a copy of this independent report, which has never been made public until now. The report concluded that de la Plaza’s death was clearly a homicide. But despite this finding and the opinion of French investigators, San Francisco authorities still classify de la Plaza’s death as “undetermined” - putting the case at the center of an international debate.

Maureen Maher reports for "48 Hours Mystery," Saturday, Nov. 14 at 10 p.m. ET/PT.