Colleen Ritzer was killed by Philip Chism, a 14-year-old freshman in her ninth-grade algebra class at Danvers High School in Massachusetts. Chism attacked the 24-year-old teacher inside a second-floor school bathroom on the afternoon of October 22, 2013, then moved her body to the woods behind the building. He was arrested that night, tried as an adult, and in December 2015 convicted of first-degree murder.
Who Philip Chism Was
Chism was born in January 1999 in Tennessee and had recently moved to Danvers with his mother. He had been enrolled at Danvers High School as a ninth grader for only a few weeks before the killing. He was 14 years old.
Colleen Ritzer was in her second year teaching math at the school, about 25 miles north of Boston. Students and colleagues described her as unusually kind, the kind of teacher who noticed a struggling student and offered extra help.
How the Killing Happened
Prosecutors told the jury that Chism arrived at school that morning with a blue hooded sweatshirt, gloves, a ski mask, and a box cutter. They said he came to school with “a terrible purpose.”
After classes ended, Ritzer asked Chism to stay for extra math help. A classmate who was present recalled that their conversation turned to Tennessee, Chism’s home state, and that Chism became visibly upset and began talking to himself. Ritzer noticed and changed the subject.
At about 2:54 p.m., school surveillance cameras captured Ritzer leaving her classroom and walking toward a second-floor student bathroom. Seconds later, Chism emerged wearing the hooded sweatshirt, put on gloves, and followed her in carrying the box cutter. Inside, he stabbed her repeatedly.
During the attack, a 17-year-old senior, Danielle Bedard, opened the bathroom door. She testified that she saw someone’s bare lower half leaning toward the sinks but could not see the upper body, assumed a person was changing clothes, and left. She said she heard nothing unusual, though another witness later described the bathroom as looking like a “slaughterhouse.”
Chism left the bathroom and returned with a recycling bin. Surveillance footage showed him, by then wearing a ski mask, dragging the bin out of the school and toward the wooded area behind it. In the woods he sexually assaulted Ritzer’s body with a tree branch. A handwritten note found near the body read, “I hate you all.” At around 3:30 p.m., a parent at the school saw Chism running away from the building. By 4:00 p.m., he had re-entered the school barefoot.
The Arrest
That evening, Ritzer’s family grew worried when she did not come home. Her father drove to the school and found her car in the parking lot but no sign of her inside. The family reported her missing, and police began reviewing the school’s surveillance footage, which showed Chism following Ritzer, the recycling bin being dragged outside, and his movements through the afternoon.
In the early hours of October 23, a police officer spotted Chism walking along a highway in a neighboring town. In his backpack, which he described as containing “survival gear,” officers found a bloodstained box cutter with an exposed one-inch blade, along with Ritzer’s wallet, credit cards, driver’s license, and underwear. Asked about the blood on his clothing, Chism said it came from “the girl.” Ritzer’s body was found shortly afterward in the woods behind the school, partially covered with leaves.
The Trial and Conviction
Chism was charged with first-degree murder, two counts of aggravated rape, and armed robbery. Under Massachusetts law, a juvenile aged 14 or older charged with murder is tried in adult court.
His defense team conceded that he killed Ritzer but argued he suffered from severe mental illness and could not be held criminally responsible, asking the jury to return a verdict of not guilty by reason of insanity. The prosecution pointed to the gloves, mask, and box cutter he brought to school that day, and to his efforts afterward to avoid detection, as evidence of planning.
In December 2015, after roughly ten hours of deliberation, the jury found Chism guilty of first-degree murder, one count of aggravated rape, and armed robbery. He was acquitted on the second aggravated rape charge.
The Sentence
Prosecutors sought consecutive sentences that would have kept Chism in prison for at least 50 years before any parole hearing. His defense asked for concurrent sentences with parole eligibility when he turned 40. In February 2016, the judge sentenced Chism to life in prison with eligibility for parole after 25 years.
The ceiling on that sentence came from a January 2014 ruling by the Massachusetts Supreme Judicial Court holding that all life-without-parole sentences for juveniles are unconstitutional under the state’s Declaration of Rights. That ruling meant Chism was always going to receive a sentence that included eventual parole eligibility.
The Assault on a Social Worker in Custody
While awaiting trial at a juvenile facility in Dorchester, Chism attacked a female social worker. He confronted her with a pencil, placed both hands around her neck, choked her, and pushed her against a cinder block wall in a bathroom. When she freed one of his hands from her throat, he punched her repeatedly in the face, head, and jaw. Chism later admitted to the attack and received a sentence of 17 to 20 years, to run concurrently with his murder sentence.
The Ongoing Appeal
Chism has appealed his conviction. In Commonwealth v. Chism, heard by the Massachusetts Supreme Judicial Court in 2025, his attorneys argued that the trial judge impeded his defense by excluding expert testimony about brain scans, placing limits on expert witnesses regarding his statements, allowing improper cross-examination of defense experts, and forcing disclosure of psychological test data.
How Colleen Ritzer Is Remembered
Ritzer’s family and friends established the Colleen E. Ritzer Memorial Fund, which awards scholarships and grants centered on kindness and education. Since 2014, the community has held the Step Up for Colleen 5K Walk/Run each year, with net proceeds going to the scholarship fund. The 12th annual event took place in May 2025 at Andover Central Park, drawing a large crowd of runners and walkers wearing pink.