The Clark County Sheriff’s Office (CCSO) is seeking the public’s assistance in gathering information related to a series of disappearances and homicides from the early 1970s believed to be connected to serial killer Warren Leslie Forrest.

In early 2024, Clark County Sheriff John Horch re-established an active Cold Case team focused on crimes committed by Forrest, who is currently serving two life sentences for the 1974 murder of Krista Kay Blake and the 1974 murder of Martha Morrison. Forrest, 75, is suspected in the deaths, disappearances, and assaults of seven other women and girls in Clark County between 1971 and 1974.

Forrest has been incarcerated since 1974. In 1978, he was convicted of the murder of 20-year-old Krista Blake, and in 2023, he was convicted of the murder of 17-year-old Martha Morrison. Since then, investigators have been reexamining other unsolved cases that may be linked to Forrest, including the 1974 murder of 20-year-old Carol Valenzuela, whose remains were found in proximity to Morrison’s.

Case Background

Warren Leslie Forrest was first apprehended in 1974 after kidnapping, raping, and attempting to murder a 19-year-old woman near Lacamas Lake. She survived the attack and helped lead CCSO investigators to Forrest. At the time, Forrest was employed by the Clark County Parks Department and lived in Battle Ground with his wife and two daughters.

In 1978, CCSO detectives began connecting Forrest to a series of disappearances and homicides that occurred between 1971 and 1974. These cases included:

Jamie Grissim (16) – Disappeared in December 1971
Barbara Ann Derry (18) – Murdered in February 1972
Diane Gilchrist (14) – Disappeared in May 1974
Gloria Nadine Knudson (19) – Murdered in May 1974
Norma Jean Countryman (15) – Kidnapped in July 1974
Krista Blake (20) – Murdered in July 1974
Carol Valenzuela (20) – Murdered in August 1974
Martha Morrison (17) – Murdered in August or September 1974 (remains discovered in Oct. of 1974, but not identified until July 2015)

Each of these cases shared common characteristics, including similar victim profiles, the locations of the disappearances, and the methods involved in the crimes.

On October 20, 1978, while a patient at Western State Hospital, Forrest was charged with first-degree murder in the killing of Krista Blake, whose remains were discovered in 1976. During his trial, a survivor from Forrest's earlier attack provided testimony about the violence he inflicted, including the use of an air pistol. Investigators seized the weapon from Forrest’s home in October 1974, and it became key evidence in his conviction. He was found guilty and sentenced to life imprisonment.

Despite his conviction, Forrest has continued to file parole applications, all of which have been unsuccessful due to his status as a suspect in multiple violent crimes.

In 2014, CCSO Major Crimes and Cold Case investigators re-examined evidence from several cases. They sent the air pistol used by Forrest to the Washington State Patrol Crime Laboratory, where a bloodstain was discovered that matched Martha Morrison’s DNA. This breakthrough led to Forrest being charged with her murder in December 2019. He was extradited to Clark County in early 2020, pleaded not guilty, and was convicted in 2023.

Current Investigation

The CCSO Cold Case Team is now focusing on the murder of Carol Valenzuela, whose remains were found near those of Martha Morrison. Both women disappeared during an 11-week period in 1974 between the murder of Krista Blake and the attempted murder of a woman at Lacamas Lake. Valenzuela and Morrison’s bodies were found in a densely wooded area of Dole Valley in eastern Clark County.

CCSO investigators are working to analyze trace evidence, including hair and nail samples recovered from Forrest’s van, which was used in several of his crimes. Advancements in DNA technology are now enabling further analysis of these samples to link them to unsolved cases.

Cold Case investigators are committed to bringing justice to the victims and their families. They are also focused on locating the remains of Jamie Grissim and Diane Gilchrist, whose disappearances remain unsolved. Grissim’s personal identification was recovered in the same area where Morrison and Valenzuela’s remains were found.

Further information and case updates will be issued as developments are made. The Clark County Sheriff’s Office urges anyone with information about these cases to contact the Cold Case Tip Line at 360-397-2036.

Source: Clark County Sheriff's Office