Prosecutors say Anthony DeMayo told police he had wanted to kill someone for a long time.

DANVERS, Mass. — An 18-year-old high school senior has been charged in the killing of a 68-year-old ICU nurse found dead inside her Danvers home, a case prosecutors say began with a random break-in and ended when police in another city encountered him carrying a blood-stained knife.

Anthony DeMayo, of Lynn, pleaded not guilty in Salem District Court to murder and armed home invasion in the death of Janet Swallow, a longtime nurse at Lahey Hospital & Medical Center. Authorities say the attack appears to have been random and that they have found no connection between DeMayo and Swallow. The case has drawn attention across the North Shore because it tied together a quiet residential street in Danvers, a witness report in Lynn, and a court proceeding that quickly turned to questions about the defendant’s mental state, public safety and how the killing unfolded.

Investigators say the timeline began late March 11 and stretched into the next day. According to prosecutors, DeMayo later told police he drove around the area looking for a house to enter before settling on Swallow’s home on Amherst Street. They say he got in through a kitchen window, moved through several rooms and found Swallow asleep in bed. Prosecutors told the court that he stabbed her in the neck and left her bleeding on the floor after his knife became stuck. By Thursday afternoon, the case shifted to Lynn, where Ashley O’Brien told local television she saw a young man on Standish Road carrying a large knife and acting in a way that alarmed her. “He looked right in my eyes,” O’Brien said, adding that she felt he was still looking to hurt someone.

Lynn police responded to the 911 call and found DeMayo acting erratically while carrying a knife with what authorities described as a reddish-brown stain. He was taken to Salem Hospital. Prosecutors say that during the police response, DeMayo told officers he had killed a woman in Danvers the night before. Investigators then obtained a search warrant for his Lynn home, where they say they found blood-stained clothing. Cellphone data also placed his phone in Danvers, where it remained in one area around midnight into the early morning, according to reporting based on court documents. Danvers police then went to Swallow’s home for a well-being check and found her dead. Officials have not said that anything was stolen, and prosecutors said the home did not appear to have been targeted for a personal reason.

Swallow’s death landed heavily in Danvers and beyond because she was not only the victim named in charging papers but also a longtime health care worker known in her community. NBC Boston reported she worked as an ICU nurse at Lahey Hospital in Burlington and was a longtime Danvers resident. A hospital statement described her as a beloved and valued member of the nursing staff. Local reporting after the arraignment also described a broader family life that included two sons, a stepson, a granddaughter and longtime interests outside work. Those details have sharpened the public sense of loss in a case authorities say was sudden and unprovoked. Essex County District Attorney Paul Tucker called it a terrible tragedy for the Swallow family, the town and Bishop Fenwick High School, where DeMayo was a senior.

The first court hearing added a legal dimension that went beyond the charging language. Before the arraignment fully proceeded, a court psychologist said DeMayo showed depressive symptoms and suicidal thinking and raised concerns about his rational understanding of the proceedings. Judge Joanna Rodriguez ordered him held without bail and sent for a mental health evaluation at Bridgewater State Hospital. A not guilty plea was entered on his behalf. The district attorney’s office said he was due back in court April 1 for a probable cause hearing, and later local reporting said a grand jury indicted him April 6 on murder and home invasion charges in Essex County Superior Court. Itemlive reported he remained in custody at Bridgewater and was scheduled to appear in Superior Court on May 11 at 9:30 a.m.

The public record still leaves important questions unanswered. Authorities have described the killing as random, but they have not publicly explained why Swallow’s home was chosen over others DeMayo allegedly passed while driving around. They have not released a more complete account of the hours between the alleged break-in and the Lynn encounter, nor have they detailed whether additional forensic testing on the knife, clothing or phone data may shape later court filings. They also have not offered a fuller explanation of the defendant’s mental condition beyond the brief courtroom statements by the psychologist. What has been made clear is the narrow chain that broke the case open: a neighbor’s alarm, a 911 call, a police stop in another city, and a defendant’s reported statement that directed investigators back to Amherst Street.

For residents, the case has left two overlapping images: the private stillness of a woman asleep in her own home and the public unease of a suspect walking through another neighborhood in broad daylight with a knife. Danvers Police Chief James Lovell said after the arrest that there was no ongoing threat to the public tied to the homicide. Bishop Fenwick President Tom Nunan Jr. also said the reported facts did not indicate a threat to the school community and that support was being made available. Those assurances may calm immediate fears, but they do not erase the shock carried by witness accounts and the details laid out in court, where the killing was described as both deliberate and, as far as investigators can tell, disconnected from any prior relationship.

DeMayo remains charged in Swallow’s death, and the next major step now is his scheduled May 11 Superior Court appearance following the April 6 indictment. The investigation remains open as prosecutors continue to build the case.

Author note: Last updated April 7, 2026.