Diane Hamill Metzger was a Pennsylvania woman convicted of first-degree murder in 1976 for her role in the killing of Martha “Marti” Metzger, her husband’s estranged first wife. She received a mandatory life sentence and served more than 43 years at the State Correctional Institution at Muncy before dying there in January 2019.1Women Lifer’s Resume Project of PA. Archive
The 1974 Killing of Martha Metzger
Martha Metzger disappeared from her home in Delaware County, Pennsylvania, on August 28, 1974.2Gil Spencer Blog. Diane Metzger Show She was the estranged wife of Frank A. Metzger, who was involved with Diane Hamill at the time. Frank entered Martha’s home that night and killed her by strangling her with a rope and suffocating her with a washcloth forced into her mouth and taped over. Her body was later found in Erie County, New York.3vLex. Commonwealth v. Metzger
Eleven days after Martha vanished, Frank and Diane married.4Delaware County Daily Times. Today in Delaware County History, July 18 The couple took Martha’s four sons and fled, abandoning the boys at a hotel in Buffalo, New York, before continuing west. They were arrested on July 11, 1975, in Boise, Idaho, and returned to Delaware County to stand trial.3vLex. Commonwealth v. Metzger
A Circumstantial Case at Trial
On March 4, 1976, a Delaware County jury found Diane guilty of first-degree murder, burglary, and criminal conspiracy.3vLex. Commonwealth v. Metzger Frank was convicted of first-degree murder and sentenced to life without parole.2Gil Spencer Blog. Diane Metzger Show
The Commonwealth’s case against Diane was entirely circumstantial. Prosecutors presented no direct physical or testimonial evidence placing her at the scene of the killing. Prosecutor Ed Weiss argued she had helped plan the murder as well as participate in it.2Gil Spencer Blog. Diane Metzger Show
Frank took the stand and said he acted alone. He testified that he struck Martha twice with a flashlight, used a rope to drag her body to a car, and told Diane what had happened only afterward. Diane testified that she had waited in a car outside and knew nothing about the crime until Frank explained it to her later.3vLex. Commonwealth v. Metzger
On rebuttal, the Erie County medical examiner testified that Martha died from asphyxiation caused by strangulation and suffocation, not from blows to the head, and that the victim’s scalp showed no hemorrhages. That contradicted Frank’s account and left the jury to decide whether his confession was truthful or an attempt to shield Diane.3vLex. Commonwealth v. Metzger
Life Sentence and Appeal
Diane was sentenced on November 16, 1977, to mandatory life imprisonment for first-degree murder, with concurrent terms of seven and a half to fifteen years on the burglary and conspiracy counts. The sentence was briefly vacated for evidentiary hearings and reimposed on January 4, 1980.3vLex. Commonwealth v. Metzger
On direct appeal, the Pennsylvania Supreme Court decided Commonwealth v. Metzger, 450 A.2d 981, 498 Pa. 678 (Pa. 1982). Her central argument was that the trial judge had wrongly denied a continuance so the defense could retain an expert pathologist to challenge the medical examiner’s rebuttal. Justice McDermott, writing for the court, called the mandatory-life posture of the case a “unique situation,” but the decision did not lead to her release. Her conviction and life sentence stood.3vLex. Commonwealth v. Metzger
Four Decades at Muncy
Diane spent the rest of her life at the State Correctional Institution at Muncy, Pennsylvania’s primary women’s prison, and became a familiar name in advocacy efforts for incarcerated women. Former Pennsylvania Attorney General Ernie Preate publicly supported her clemency and called her a “model prisoner” who had served more than thirty years.2Gil Spencer Blog. Diane Metzger Show Her case was profiled on the television series Women Behind Bars in April 2008, which renewed public debate over her guilt and possible release.
She was never granted clemency or parole. She died in January 2019, having served more than 43 years. The Women Lifer’s Resume Project of Pennsylvania listed her dates as July 1949 to January 2019 and noted she would be “greatly missed by so many friends and family members.”1Women Lifer’s Resume Project of PA. Archive
Would Pennsylvania’s Recent Sentencing Changes Have Helped
On March 26, 2026, the Pennsylvania Supreme Court ruled in Commonwealth v. Derek Lee that mandatory life without parole for second-degree (felony) murder violates the state constitution’s ban on “cruel punishments.”5The Sentencing Project. Pennsylvania Supreme Court Ends Mandatory Life Without Parole for Those Who Did Not Intentionally Kill The ruling applies only to second-degree murder. It has no direct legal bearing on first-degree murder convictions like Diane Metzger’s.6Abolitionist Law Center. FAQ About the Derek Lee Felony Murder Ruling Pending legislation to allow parole eligibility after 25 years for felony murder lifers is likewise limited to second-degree cases.7Spotlight PA. Pennsylvania Felony Second Degree Murder Supreme Court Ruling Even had Diane lived to see the change, her first-degree conviction would have placed her outside its reach.