DATELINE NBC's Josh Mankiewicz guest

Dateline NBC's Josh Mankiewicz reports on the fascinating case of Sherri Rasmussen. Almost 20 years after Sherri Rasmussen is found shot to death in what appeared to be a robbery, detectives take a fresh look at the cold case that was buried in the archives at the Los Angeles Police Department. Thanks to major advances in DNA testing technology, a new lead in the case points toward a former girlfriend of Sherri's husband-- who also happens to be a decorated detective with the L.A.P.D.