Offender Record · OFF-2026-041
William Edward Cook Jr.
Also known as Billy Cook, Billy Boy, Cockeyed Cook
Sex
Male
Race
White
Eyes
deformed right eye that could not close
Born
1928
Custody
Deceased
States
MO, MX, CA, OK, TX
Distinguishing featurescongenital eye defect; right eye unable to close completely, earning nickname 'Cockeyed'; had 'HARD LUCK' tattooed on left hand
Custody
Executed by gas chamber on December 12, 1952, at San Quentin State Prison, San Quentin, California
This record documents arrests, charges and convictions reported by courts, law enforcement agencies and news organizations. Every statement is tied to a cited source with an archived copy. A charge is an accusation, not proof of guilt; a person charged is presumed innocent unless convicted. Solve the Case does not allege that this person committed any offense beyond what the cited records state, and this record is not a suggestion that the person is connected to any unsolved case. How records are built, corrected and removed.
Summary of the record
William Edward Cook Jr. was a spree killer convicted of federal kidnapping and first-degree murder. Between December 30, 1950 and January 6, 1951, he kidnapped and killed six people across Missouri and California, including five members of the Mosser family and traveling salesman Robert Dewey. Cook pleaded guilty to five federal counts of kidnapping in Oklahoma for the Mosser murders and received 300 years; he was then convicted of first-degree murder in California for Dewey's death and received the death penalty. Cook was executed by gas chamber at San Quentin on December 12, 1952, at age 23.
Documented Arrests, Charges and Convictions
Dispositions are shown exactly as the cited records report them. Pending charges are updated when a court acts; a record with no remaining conviction or pending charge is removed from the site.
Offense date Dec 29, 1950, Oklahoma, Missouri
Kidnapping
United States District Court, Oklahoma (Federal Kidnapping Act) · U.S. District Court, Oklahoma City · Federal Kidnapping Act · Arrested Jan 15, 1951 · Convicted Convicted · Sentence: 300 years (60 years for each of five counts, consecutive); to be served at Alcatraz Federal Penitentiary
Cook kidnapped Mosser family (Carl Mosser, 33; Thelma, 29; Ronald, 7; Gary, 5; Pamela Sue, 3) on December 29, 1950 near Claremore, Oklahoma after they picked him up hitchhiking. He held them hostage with a .32-caliber pistol and forced them to drive aimlessly across Oklahoma, Texas, and Arkansas for three days. On January 2, 1951, Cook shot and killed all five family members including the family dog near Joplin, Missouri, and dumped their bodies in an abandoned mine shaft. Cook pleaded guilty to five counts of kidnapping to avoid death penalty; court permitted plea due to disputes over Cook's mental health.
SourcesBilly Cook (criminal); Billy 'Cockeyed' Cook: Portrait of an American Spree Killer, 1951; Badman Billy Cook; The Mosser Massacre and Tulsa's forgotten role in the case
Offense date Jan 06, 1951, Imperial County, California
First Degree Murder
State of California, Imperial County · California Superior Court, El Centro · California Penal Code (First Degree Murder) · Arrested Jan 15, 1951 · Convicted Convicted · Sentence: Death by gas chamber
Cook kidnapped Robert Dewey, a 31-32 year old traveling salesman from Seattle, on January 6, 1951 in Imperial County, California. During the drive, Dewey tried to wrestle the gun from Cook but was wounded in the attempt. Cook shot Dewey in the head, killing him. Dewey's body was found in Waldrip's abandoned police car near Ogilby, California; Cook abandoned Dewey's own vehicle in Mexicali, Mexico. Cook was convicted of first-degree murder after jury found him guilty in November 1951 after 50 minutes of deliberation.
SourcesBilly Cook (criminal); Billy 'Cockeyed' Cook: Portrait of an American Spree Killer, 1951; The Kidnapping and Slaying of the Mosser Family; Billy 'Cockeyed' Cook: Portrait of an American Spree Killer, 1951
Pattern and Background
Victim counts and the pattern of the offenses as stated by courts, agencies and the cited reporting. Suspected counts are what officials have said publicly, not a finding of this site.
6
Victims convicted
0
Victims confessed
0
Victims suspected
Active years
1950–1951
Stated motive
Financial gain
Range from home
interstate
Education
some high school
Marital history
Never married
Children
0
Died
1952-12-12 · executed
Places Lived, Worked and Frequented
Each place and date range comes from a cited record. Dates marked approximate are as reported. Know a place that is missing? Use Edit record under the photo; a moderator reviews it before it appears.
CA
Blythe, California
1950 – Dec 24, 1950 · Only legitimate job; dishwasher at restaurant; left without notice on Christmas Eve 1950
California
Mar 20, 1951 – Oct 13, 1951 · Alcatraz Federal Penitentiary · Federal 300-year sentence for kidnapping; transferred to California for murder trial
El Centro, California
Oct 13, 1951 – Nov 23, 1951 · Held for California murder trial for Robert Dewey; convicted November 23, 1951
San Quentin, California
Nov 28, 1951 – Dec 12, 1952 · San Quentin State Prison · Death row; sentenced to death November 28, 1951; executed by gas chamber December 12, 1952
MO
Joplin, Missouri
1928 – 1933 · Born in Joplin; lived with family until mother died (1933)
Joplin, Missouri
approx. 1940 – 1943 · In and out of juvenile detention
Missouri
approx. 1943 – 1946 · Jail; escaped March 23, 1946; recaptured August 15, 1946
Jefferson City, Missouri
1946 – 1950 · Missouri State Penitentiary
Joplin, Missouri
Jun 1950 – Dec 1950 · Released from prison June 16, 1950; returned briefly to reunite with father before heading west
MX
Santa Rosalía, Baja California Sur, Mexico
Jan 09, 1951 – Jan 15, 1951 · Arrested by local police chief Luis Parra in Santa Rosalía; transferred to FBI; extradited back to United States January 15, 1951
OK
Oklahoma City, Oklahoma
Jan 22, 1951 – Mar 20, 1951 · Held for trial on federal kidnapping charges; sentenced March 20, 1951
TX
El Paso, Texas
Dec 24, 1950 – Dec 27, 1950 · Purchased .32-caliber pistol in El Paso after leaving California
Known Vehicles
Vehicles and approximate dates of ownership or use, as reported in the cited records. A photo next to a vehicle is the vehicle itself as published.
1947 blue Buick Sedan – Robert Dewey's vehicle
Jan 06, 1951 – Jan 06, 1951
Used in kidnapping and murder of Robert Dewey; abandoned in Mexicali, Mexico
1949 unknown Chevrolet Sedan – Mosser family car; used in kidnapping and murders
Dec 29, 1950 – Jan 02, 1951
Vehicle picked up on highway by Mosser family on Dec 29, 1950; abandoned in Tulsa, Oklahoma after murders
Photographs by Year
Photo from en.wikipedia.org
Photo from time.com
<b>Not originally published in LIFE.</b> Spree killer William Cook sent back to the United States from Mexico after capture, January 1951.
![<b>Caption from LIFE.</b> "Circulars on Cook were posted through the Southwest and Mexico. [Robert] Dewey's murder spread panic. Citizens avoided lonely roads, 'recognized' Cook from Albuquerque to Lo](https://solvethecase9c0c8-main.s3.amazonaws.com/public/OFF-2026-041/c97f30c8-ae2d-4573-80aa-c9263934bb07.webp)
<b>Caption from LIFE.</b> "Circulars on Cook were posted through the Southwest and Mexico. [Robert] Dewey's murder spread panic. Citizens avoided lonely roads, 'recognized' Cook from Albuquerque to Lo
<b>Not originally published in LIFE.</b> A crowd in Tijuana, Mexico, watches as spree killer William Cook is sent back to the United States after capture, January 1951.
<b>Not originally published in LIFE.</b> In Tijuana, Mexico, spree killer William Cook is sent back to the United States after capture, January 1951.
Timeline
Dec 23, 1928
William Edward Cook Jr. born in Joplin, Missouri.
1933
Cook's father moved the children to an abandoned mine shaft and later abandoned them entirely; Cook became ward of state.
1933
Cook's father abandoned the family; shortly after, Cook's mother died when he was 5 years old, and Cook discovered her body.
1940
Cook in and out of juvenile detention.
1943
Cook put in jail.
Sep 1943
Cook held up and kidnapped a cab driver at age 14.
Mar 23, 1946
Cook escaped from jail.
Aug 15, 1946
Cook caught escaping from jail.
Jun 16, 1950
Cook released from Missouri State Penitentiary.
Dec 24, 1950
Cook left his dishwashing job in Blythe, California and headed toward El Paso, Texas.
Dec 27, 1950
Cook purchased .32-caliber pistol in El Paso, Texas.
Dec 29, 1950
Cook kidnapped Mosser family (five people including three children) in Oklahoma after they picked him up hitchhiking.
Jan 02, 1951
Cook shot and killed all five members of the Mosser family near Joplin, Missouri and dumped their bodies in an abandoned mine shaft.
Jan 06, 1951
Cook kidnapped and murdered Robert Dewey, a traveling salesman from Seattle, in Imperial County, California.
Jan 09, 1951
Cook arrested by local police in Santa Rosalía, Mexico.
Jan 15, 1951
Cook extradited back to the United States and returned to Oklahoma City.
Mar 20, 1951
Cook pleaded guilty to five counts of federal kidnapping and was sentenced to 300 years in prison (60 years per count, consecutive) at Alcatraz Federal Penitentiary.
Oct 13, 1951
Cook tried for first-degree murder of Robert Dewey in California.
Nov 23, 1951
Cook convicted of first-degree murder for killing Robert Dewey; jury did not recommend mercy, resulting in automatic death sentence.
Nov 28, 1951
Cook sentenced to death by gas chamber.
Dec 12, 1952
Cook executed by gas chamber at San Quentin State Prison, San Quentin, California at age 23.
Sources
Solve the Case is never the original source. Each item below is the public record a statement on this page rests on, with an archived copy where one exists.
Other government record · Find a Grave ·
William Edward 'Billy' Cook Jr.“After standing trial for the Mosser family murders and receiving a 300 year sentence, he was tried in California for the Dewey murder, for which he received the death penalty.”
Other · Murderpedia ·
William Cook“Number of victims: 6; Date of murders: January 2/6, 1951; Status: Executed by asphyxiation-gas in California at San Quentin Prison on December 12, 1952”
News report · Missouri and Ozarks History ·
The Kidnapping and Slaying of the Mosser Family“At his trial in November 1951 at El Centro, he was found guilty of first-degree murder and sentenced to death. He was executed in the gas chamber at San Quentin on December 12, 1952.”
News report · Useless Information ·
Badman Billy Cook“To avoid a possible death sentence, Cook pleaded guilty to five counts of kidnapping... The judge sentenced him to 300 years in federal prison.”
News report · Wikipedia ·
Billy Cook (criminal)“William Edward Cook Jr. was an American spree killer and mass murderer who murdered six people, including a family of five, on a 22-day rampage between Missouri and California in 1950–51”
News report · Tulsa World ·
The Mosser Massacre and Tulsa's forgotten role in the case“Around 11 a.m. that day, apparently, the Mossers came across a young hitchhiker named William Cook, who had left California on Christmas Day.”
News report · LIFE ·
Billy 'Cockeyed' Cook: Portrait of an American Spree Killer, 1951“He killed six people, including an entire family of five, during a terrifying three-week spree across several American states in early January 1951”
News report · TIME ·
Billy 'Cockeyed' Cook: Portrait of an American Spree Killer, 1951“William Cook was sentenced to 300 years in prison after being tried and convicted of the Mosser killings in Oklahoma, but was then tried, convicted and sentenced to death in California for the murder of Robert Dewey. On Dec. 12, 1952, at San Quentin, Cook was executed in the famous prison's gas chamber.”
Other · Radford University, Department of Psychology ·
Radford University serial killer biography: Cook, William“William Edward 'Billy' Cook, born December 23, 1928 in Joplin, Missouri; murdered six people, including Mosser family and Robert Dewey; executed December 12, 1952 at San Quentin”
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