Dateline S19E25 Internal Affairs (2011)

Dateline Season 19 Episode 25 Online – An attractive nurse, Sherri Rasmussen, is murdered in her own home in 1986. There are few clues, except one: a bite mark containing saliva found on Sherri's arm. But it's of little use because DNA testing is not yet available. “Internal Affairs" Josh Mankiewicz follows a cold case to its conclusion as the Los Angeles Police Department investigates its own officer for a murder.