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Assassination of William Cann

SOLVED1973Decoto neighborhood, Union City, California3 SOURCESUPDATED JUL 2026
Union City BART station — location anchor for the case
Union City BART station — location anchor for the case — Credit: CC0

On June 11, 1974, Union City, California police chief William Cann was shot while addressing a community meeting held at Our Lady of the Rosary Church in the Decoto neighborhood. The meeting had been organized to address rising community tension following the April 19, 1974 fatal shooting of 30-year-old Alberto Terrones by Union City patrolman John Miner. Terrones, who had allegedly stolen canned hams and brandished a knife at store clerks and at Miner, was shot after failing to drop the knife when ordered. Terrones died of his wounds later that evening. The shooting was found to be justifiable homicide by the Union City Police Department, city government, the local district attorney, and an Alameda County grand jury.

At the June 11 meeting, attended by about 55 people, Cann was speaking to the group in plainclothes when, at approximately 9:30 p.m., shots fired from outside through a window struck him in the neck with two .30-caliber rifle bullets. The gunman continued firing after Cann fell, wounding three others identified as Robert Portillo, Matilda Gudino, and Manuel Pena; a fourth person, Miguel Aponte, was injured while attempting to flee. Cann was hospitalized in Alameda County but never regained consciousness, dying from his injuries on August 29, 1974, at age 32. He was survived by a wife and three young children. A municipal playground, William Cann Park, was dedicated in his honor in 1975.

Following the shooting, a letter received by the San Francisco Chronicle claimed responsibility on behalf of a "Santos Rodriquez Assault Squad" of the "Chicano Liberation Front," stating the group's "Revolutionary Tribunal" had found Cann guilty of "murder and attempted coverup." Police later said the letter could not be authenticated. A subsequent communique reportedly denied the group's involvement. A 1979 U.S. Senate Judiciary Committee document noted that Officer Miner had been exonerated and reassigned to desk duty, that the Justice Department visited the community twice but declined to file civil-rights charges, and that some community members believed the killing of Cann was a "set-up," since he was regarded as one of the city officials most sympathetic to local Chicano residents.

The case remained unsolved for more than six years. It was reopened after Francisco Chavez offered information on the killing in exchange for leniency on an unrelated concealed-weapons charge. According to Chavez, the killing was carried out by four former Brown Berets from San Jose, who had originally intended to target Officer Miner and city manager William Zaner instead. In Chavez's account, the attack had been planned by Ruben Vizcarra, with Leonard Baca as the shooter and Angel Ramirez and Paul Mendoza as accomplices. Ramirez, Mendoza, and Chavez testified against Vizcarra and Baca in exchange for charges against them being dropped. Vizcarra was tried and acquitted. Baca was convicted of second-degree murder and, having already been incarcerated in New Mexico, served time for the Cann killing from 1987 to 1990. He died of a drug overdose shortly after his release.

Key facts

Victims
Matilda Gudino, Miguel Aponte, Manuel Pena, Alberto Terrones, William Cann, Robert Portillo
Date
1973
Location
Decoto neighborhood, Union City, California
Case status
solved

Case timeline

  1. 1944-04-10

    Alberto Terrones is born in Los Angeles.

  2. 1941-12-15

    William Cann is born in New York.

  3. 1973-03-05

    William Cann joins the Union City Police Department as chief of police.

  4. 1974-04-19

    Alberto Terrones is shot by Union City patrolman John Miner and dies of his wounds later that evening.

  5. 1974-06-11

    Sniper opens fire on a community meeting at Our Lady of the Rosary Church, striking Chief William Cann in the neck and wounding three others.

  6. 1974-06-21

    San Francisco Chronicle receives a letter claiming the 'Chicano Liberation Front' killed Cann; police later say it could not be authenticated.

  7. 1974-06-25

    The mother of two stabbed children confesses to killing her daughter and stabbing her son, and to fabricating an earlier story blaming an unidentified Latino attacker.

  8. 1974-08-29

    William Cann dies of his gunshot wounds without having regained consciousness.

  9. 1975

    William Cann Park is dedicated in his honor.

  10. 1979

    A U.S. Senate Judiciary Committee document reports on the Miner exoneration and Justice Department review of the case.

  11. 1981

    Four men are arrested in connection with the 1974 killing of Chief Cann, per UPI Archives.

  12. 1987

    Leonard Baca begins serving his sentence for the Cann killing.

  13. 1990

    Leonard Baca is released and dies shortly afterward of a drug overdose.

Best coverage

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People

  • Matilda Gudino

    VICTIM

    Injured by gunfire during the sniper attack on the community meeting.

  • Paul Mendoza

    CHARGED

    Identified as an accomplice in the killing; testified against Vizcarra and Baca after charges against him were dropped.

  • Miguel Aponte

    VICTIM

    Injured while attempting to flee the scene of the sniper attack.

  • Angel Ramirez

    CHARGED

    Identified as an accomplice in the killing; testified against Vizcarra and Baca after charges against him were dropped.

  • Manuel Pena

    VICTIM

    Injured by gunfire during the sniper attack on the community meeting.

  • Ruben Vizcarra

    ACQUITTED

    Identified as the planner of the attack on Cann; acquitted at trial.

  • Alberto Terrones

    VICTIM

    Fatally shot by Union City patrolman John Miner on April 19, 1974; the shooting was ruled justifiable homicide.

  • John Miner

    LAW ENFORCEMENT

    Union City patrolman who fatally shot Alberto Terrones; later exonerated and reassigned to desk duty.

  • Francisco Chavez

    CHARGED

    Informant who was originally to be the gunman but withdrew; provided information leading to arrests in exchange for leniency on a separate concealed-weapons charge and had charges dropped.

  • William Cann

    VICTIM

    Union City police chief fatally shot at a community meeting on June 11, 1974; died August 29, 1974.

  • Leonard Baca

    CONVICTED

    Identified as the shooter; convicted of second-degree murder for the killing of William Cann and served time from 1987 to 1990.

  • Robert Portillo

    VICTIM

    Injured by gunfire during the sniper attack on the community meeting.

Roles reflect public records and court outcomes at the time of writing — supporting citations are on file under Sources.

Archival records

  • Union City BART station — location anchor for the case

    archival location

    Union City BART station — location anchor for the case

    Credit: CC0 · Source

Places

Decoto neighborhood, Union City, California

37.5933, -122.0438

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Common questions

What happened to the victim?
Union City, California police chief William Cann was fatally shot by a sniper at a community meeting on June 11, 1974, amid racial tensions following the police killing of Alberto Terrones. Cann died of his wounds more than two months later. The case remained unsolved for over six years until an informant's testimony led to charges against four former Brown Berets; one was convicted, one acquitted.
Where did the crime happen?
Decoto neighborhood, Union City, California.
Who was convicted?
Leonard Baca (Identified as the shooter; convicted of second-degree murder for the killing of William Cann and served time from 1987 to 1990.).
What is the current status of the case?
Status: solved.
More cases in California

Sources

  1. ENCYCLOPEDICAssassination of William CannWikipedia · 2026-07-10
  2. PRESSContemporaneous coverage — familysearch.orgfamilysearch.org · 2026-07-10
  3. PRESSContemporaneous coverage — museumoflocalhistory.orgmuseumoflocalhistory.org · 2026-07-10