A man from Oregon pleaded guilty Wednesday to a 1979 murder in Back Bay, a crime he confessed to in 2023, authorities said. 

John Irmer, 71, was charged with first-degree murder of 24-year-old Susan Rose, whose body was found in an apartment at 285 Beacon St. on Oct. 30, 1979, according to a statement from Suffolk District Attorney Kevin Hayden. 

In August 2023, Irmer confessed to the murder at an FBI field office in Portland, Oregon. He initially spoke with federal authorities twice, each time admitting to the crime, before Boston Police Homicide Unit detectives traveled to Oregon to interview him, according to a 2023 statement of facts filed with the court.

Irmer told detectives that his decision to confess stemmed from becoming sober and “finding Jesus” after serving a lengthy prison sentence for a separate murder conviction in California, the statement of facts noted. 

Irmer described meeting the victim, identified as Rose, in Boston around Halloween 1979 while she was arguing with her boyfriend, court records indicate. 

After visiting Rose’s basement apartment and walking around Back Bay, Irmer and Rose stopped at a house under construction. As Rose walked up a set of stairs inside the house, Irmer struck her in the head with a hammer “so hard that he believes that he killed her instantly,” according to court documents. 

Irmer also confessed to sexually assaulting Rose after killing her, authorities said. 

After the murder, Irmer admitted to stealing Rose’s wallet, taking the cash, and discarding the remainder of the wallet into the Charles River before traveling by bus to New York. 

Irmer additionally confessed to committing another murder in a southern state, which authorities from that state are investigating. He also admitted to shooting someone in a different southern state, though he was uncertain if that victim died, according to court documents. 

“Irmer repeatedly stated that he wanted to do what was right and cited his finding Jesus and feeling bad about what he had done for his reason for confessing and wanting to plead guilty immediately,” the statement of facts noted. 

First-degree murder carries a mandatory life sentence without the possibility of parole, according to the Suffolk County District Attorney’s office. 

A different man was initially arrested for Rose’s murder but was ultimately found not guilty, according to Hayden. In 2005, a DNA profile was developed from sperm cells located on a broom that had been found inserted inside Rose’s body, and the person previously arrested was excluded as the source of the sperm found on the broomstick. 

Rose’s older sister presented a victim impact statement during Wednesday’s hearing, Hayden said. She held a photo of Rose from first grade, saying she wished to remember her that way.  

Rose was described by her sister as adventurous, intelligent, and motivated, with dreams of becoming a lawyer. 

“All of this was taken from her … Susie never got to finish school, get married, or have her own children,” she said. “She never got to see all the places she wanted to visit, meet new friends, or have new adventures. Her life was cut short at the age of 24.” 

Rose’s sister explained how the murder profoundly impacted her family. 

“My parents were never the same after Susie’s murder,” she said. “Though they lived long lives, they were never truly happy or at peace.” 

Mourning the loss of her only sibling, Rose’s sister shared her personal grief, saddened by the fact that her daughter would never have the chance to meet her aunt. 

“I am relieved that there is some closure to this nightmare,” she said. “I truly hope that John Irmer understands what he did because I will never forget.” 

Following the hearing, Hayden commended the investigators on the case. He also addressed Rose’s family, saying “The answers for Susan Rose’s sister and friends finally came today, though after a very long and sad period of time. I hope other families affected by John Irmer’s murderous behavior find similar answers.”