Before you continue
This case involves crimes against children. Casepin presents the record in neutral, non-graphic language. Choose whether to continue.
Solved case · 1986
The short answer
On October 5, 1986, Hells Angels members Gerry "Butch" Lester and Charles "Chuck" Diaz killed William Grondalski, his wife Patricia, his stepson Jeremy, and his five-year-old daughter Dallas at their home in Fort Bragg, Mendocino County, California, then burned the house to destroy evidence.
The coverage index
No one's coverage is attached to this file yet.
Know great coverage of this case?
A documentary, a podcast episode, a careful long-form video. Suggest it and an editor will review it before it appears here.
Suggest coverage for Grondalski family murdersThe case file
William "Billy" Grondalski, an oil refinery worker, joined the Vallejo chapter of the Hells Angels in 1982. He struggled with substance abuse and, following internal club violence in 1986 involving an expelled member named Terry Dalton, told his estranged wife Patricia "Patty" Kast that he wanted to leave the club. The couple reconciled, and Billy added a tattoo reading "84 In 86 Out" beneath his Hells Angels death's head tattoo. Because he did not cover or remove his club tattoos after leaving, the Vallejo chapter, under new president Gerry "Butch" Lester, considered him "in bad standing" and sought him out. The family, including teenage son Jeremy and five-year-old daughter Dallas, moved to Fort Bragg on October 1, 1986, moving furniture only at night out of fear.
On October 5, 1986, Lester and Charles "Chuck" Diaz, having borrowed a truck from fellow Hells Angel Michael "Little Mike" Tankersley, went to the Grondalski home. Lester shot and killed Billy, then the pair killed Patty, Jeremy, and Dallas to eliminate witnesses. The killings involved gunfire and stabbing, and the perpetrators mutilated Billy's body to remove his club tattoo. Other Hells Angels associates, including Tankersley, Sammie Lester, and Charles Haas, assisted in destroying evidence, including melting the weapons and burning the house, which damaged the victims' remains.
Mendocino County Detective Sergeant Philip Pintane took over the investigation in 1988 but initially made little progress; police had mistakenly believed the killings occurred a day later than they had. In 1993, Charles Haas, then facing a lengthy prison sentence in Arizona for drug offenses, offered information in exchange for leniency and revealed the correct date of the murders. Working with Mendocino County District Attorney Susan Massini, Pintane built a case, and in May 1995 Lester and Diaz were arrested on first-degree murder charges. Tankersley, tracked down in Arkansas, eventually agreed to testify for the prosecution.
Lester was tried three times; the first two trials in 1997 ended in hung juries before he was convicted of first-degree murder in a third trial in late 1997 and sentenced to life imprisonment. Diaz's case was delayed by legal complications, including a conflict of interest involving defense attorney Norman Vroman's later election as district attorney, leading the state to take over prosecution. Diaz was tried beginning March 2004 alongside co-defendants Mary Anne Roach, Sammie Lester, and Robert Huffman on related obstruction and arson-related charges. On May 5, 2004, a jury convicted Diaz of four counts of first-degree murder.
20 dated entries · 1982–2004
William Grondalski joins the Vallejo chapter of the Hells Angels.
Patricia Grondalski files for divorce, citing her husband's involvement with the Hells Angels.
Hells Angel Terry Dalton is expelled from the Oakland chapter for stealing.
Sonny Barger summons the Vallejo chapter to Oakland, where several members are beaten for maintaining contact with Dalton.
Barger appoints Gerry 'Butch' Lester as the new president of the Vallejo chapter.
Lester reports to Barger that Grondalski is 'in bad standing' and his tattoos need to be covered.
The Grondalski family moves to a new house in Fort Bragg.
Billy, Patricia, Jeremy, and Dallas Grondalski are murdered at their Fort Bragg home by Gerry Lester and Charles Diaz; the house is later set on fire.
The burned house and the family's deaths are reported to Mendocino County police.
Detective Sergeant Philip Pintane takes charge of the investigation.
Charles Haas, convicted of drug possession in Arizona, offers information about the murders in exchange for a reduced sentence.
A deal is struck for Haas to provide a recorded statement to investigators.
Gerry Lester and Charles Diaz are arrested on first-degree murder charges.
Lester's first trial ends in a hung jury.
Lester's second trial begins and again ends in a hung jury.
Lester is convicted of first-degree murder at his third trial and sentenced to life imprisonment.
Norman Vroman, former defense lawyer for Lester and Diaz, is elected district attorney of Mendocino County.
A grand jury indicts Diaz for first-degree murder after the state assumes prosecution due to a conflict of interest.
The trial of Charles Diaz, along with co-defendants Mary Anne Roach, Sammie Lester, and Robert Huffman, begins.
A jury finds Charles Diaz guilty of four counts of first-degree murder.
12 named in this file
Victims first. Every legal label is set from public records and court outcomes, not from the prose.
Killed on October 5, 1986; five-year-old daughter of William and Patricia Grondalski.[3]
Killed on October 5, 1986; teenage stepson of William Grondalski.[3]
Killed on October 5, 1986; wife of William Grondalski.[3]
Killed on October 5, 1986; former Hells Angels member.[3]
Convicted of four counts of first-degree murder on May 5, 2004.[3]
Convicted of first-degree murder in 1997 and sentenced to life imprisonment after two prior hung-jury trials.[3]
Charged with obstruction of justice and threatening witnesses in connection with the case.[3]
Charged in connection with providing the van used in the arson of the Grondalski house.[3]
Charged with obstruction of justice in connection with the case.[3]
California assistant district attorney who took over prosecution of Charles Diaz due to a conflict of interest.[3]
Mendocino County Detective Sergeant who led the investigation from 1988 onward.[3]
Mendocino County District Attorney who prosecuted Gerry Lester.[3]
From the record
3 cited
Coverage is not a source: every fact in this file rests on the records below.
Pressupi.comAccessed Jul 10, 2026
Pressdeseret.comAccessed Jul 10, 2026
EncyclopedicWikipediaAccessed Jul 10, 2026
Trust
Are you family of someone named in this file? Corrections and removal requests from victims’ families are prioritized.
Near this case
Image record·Editorial use·SourceSOLVEDListenCalifornia State Route 1 near Westport, Mendocino County, California · 2010s
On March 26, 2018, Jennifer Hart drove the family's SUV off a cliff on California State Route 1 in Mendocino County, killing herself, her wife Sarah Hart, and their six adopted children in a ruled murder–suicide.
Credit: Mendocino County Police Department·Public domain·SourceUNSOLVEDListenHighway 20 near Willits, Mendocino County, California (remains recovery site) · 1970s
Two teenage best friends from Forestville, California, vanished on December 16, 1978, after reportedly setting out to hitchhike to a party in Santa Rosa. Their duct-taped, buried remains were found in July 1979 off Highway 20 near Willits, but the bodies went unidentified for 36 years—partly because one victim's skeleton was mistakenly classified as male—until DNA confirmed their identities in 2015. The case remains unsolved.
Rollerville Cafe area, Point Arena, California · 2010s
Asha Kreimer, a 26-year-old dual US-Australian citizen, vanished on September 21, 2015, after walking away from a cafe restroom in Point Arena, California, shortly after being released from a hospital following a mental health crisis. She has not been found.
Credit: Jgb23·CC BY-SA 4.0·SourceSOLVEDListenBlacktown / Prospect, New South Wales, Australia · 1986
Anita Cobby, a 26-year-old nurse, was abducted while walking home from Blacktown railway station in Sydney on 2 February 1986, then raped, tortured and murdered by five men. Her body was found two days later; all five perpetrators were convicted in 1987 and sentenced to life imprisonment without parole.
Credit: D4444n at en.wikipedia·CC BY-SA 3.0·SourceSOLVEDListenGrand Hotel, Brighton, England · 1984
On 12 October 1984 the IRA detonated a long-delay bomb at the Grand Hotel in Brighton in an attempt to assassinate Prime Minister Margaret Thatcher and her cabinet during the Conservative Party Conference. Five people were killed and more than thirty injured; Thatcher was uninjured. IRA member Patrick Magee was convicted in 1986 and sentenced to eight concurrent life terms.
Credit: English Wikipedia·Editorial use·SourceSOLVEDListenMercy Road offramp, Interstate 15, San Diego County, California · 1986
Cara Knott, a 20-year-old San Diego State University student, disappeared on December 27, 1986, while driving home from her boyfriend's house. Her body was found the next day below a bridge near an isolated freeway offramp. California Highway Patrol officer Craig Alan Peyer was convicted of her murder in 1988 after a second trial.
