Colleen Ritzer, The Math Teacher Who Was Killed After School By Her Ninth-Grade Student

Published April 14, 2024
Updated April 15, 2024

Colleen Ritzer was a beloved teacher at Danvers High School in Massachusetts — then 14-year-old Philip Chism raped her and slit her throat with a boxcutter in a bathroom after class on October 22, 2013.

Warning: This article contains graphic descriptions and/or images of violent, disturbing, or otherwise potentially distressing events.

Colleen Ritzer

Colleen E. Ritzer Memorial FundTeaching was Colleen Ritzer’s lifelong passion, but she was murdered just months into her second year working at Danvers High School.

In the early morning hours of Oct. 23, 2013, math teacher Colleen Ritzer was found dead behind Danvers High School in Massachusetts. She’d been sexually assaulted, her throat was slit, and a note beside her body read: “I hate you all.”

Colleen Ritzer was a well-liked teacher, and the police initially had no idea who could have a motive to kill her. Then, they learned that one of her ninth-grade students, 14-year-old Philip Chism, had been found walking along the side of a highway with a bloody box cutter — and the pieces began falling into place.

While staying after school for extra help on Oct. 22, Chism had followed Ritzer into a bathroom, raped her, and strangled her before dragging her body into the woods behind the building in a recycling bin. There, he’d assaulted her once again and slit her throat.

Philip Chism was tried as an adult and sentenced to life in prison, but no amount of punishment would bring back Colleen Ritzer, the beloved teacher who was brutally murdered at just 24.

Colleen Ritzer’s Life As A Teacher At Danvers High School

Colleen Ritzer had always dreamed of becoming a teacher. Her mother, Peggie Ritzer, once recalled, “She wanted to be a teacher from the time she was in preschool. As she got older, she excelled in math, so she wanted to teach math.”

Ritzer graduated magna cum laude from Assumption College in Worcester, Massachusetts, in 2011 with a degree in mathematics and a concentration in secondary education. She accepted a job at a middle school teaching eighth-grade math.

Her colleague Charlotte Dzerkacz told CNN in 2013 that Ritzer knew just a few weeks into her first year in the classroom that she’d found her calling. “She cared about every single student and put in many hours after school every day, always thinking about how she could be better and better help students,” said Dzerkacz. “She was truly a beautiful person.”

Colleen Elizabeth Ritzer

ZUMA Press, Inc. / Alamy Stock PhotoColleen Ritzer was just 24 years old when she was murdered by her 14-year-old student.

Ritzer was excited to begin teaching geometry and algebra at Danvers High School in 2012. She frequently used social media to interact with her teenage students. “Full school week ahead,” she once wrote. “That can only mean one thing: lots of math fun.”

She even described herself in her Twitter profile as a “math teacher often too excited about the topics I’m teaching.”

So, it was a shock to everyone when Colleen Ritzer was brutally murdered just two months into her second year at the school.

The Murder Of Colleen Ritzer

On Tuesday, Oct. 22, 2013, Colleen Ritzer asked Philip Chism to stay after school for some extra help. Another student later recalled that Ritzer had asked Chism about his recent move from Tennessee, which made Chism visibly upset. Ritzer quickly changed the subject, but her innocent question may have set off the grisly chain of events that followed.

According to a timeline reported by The New York Times, at 2:54 p.m., Ritzer left the classroom to walk to the bathroom down the hall. Security footage from the school showed Chism following her a minute later. He pulled his hood over his head and entered the women’s restroom behind her.

At 3:06 p.m., a female student went into the bathroom and immediately turned back around. She later testified that she saw a bare bottom and thought she’d walked in on someone changing clothes.

One minute later, Chism left the bathroom carrying the pants that Colleen Ritzer had been wearing. He returned at 3:16 p.m. with a recycling bin, which he dragged back out of the school at 3:22, this time wearing a black ski mask as well.

Danvers High School

Wikimedia CommonsDanvers High School in 2014.

When Chism failed to return home that evening, his mother reported him missing. An officer located him walking on a highway shortly after midnight and found a bloody box cutter in his possession. When he asked where the blood was from, Chism simply responded: “The girl.” Chism also had Ritzer’s credit card and underwear in his possession.

At the same time, police were searching for Ritzer, who had also been reported missing. A few hours later, they found her body beneath some leaves near Danvers High School. She was naked from the waist down, and her corpse had been “sexually staged.” Chism’s backpack and school ID were also discovered nearby.

The authorities quickly put two and two together and arrested Philip Chism for Colleen Ritzer’s murder.

The Trial Of Philip Chism

Prosecutors decided to try Chism as an adult due to the brutality of the crime. An investigation into Colleen Ritzer’s death revealed that he’d raped her in the school bathroom — and a female student had unknowingly walked in on the act — before stuffing her into the recycling bin and dragging her into the woods. In fact, according to, Ritzer was likely still alive when Chism sexually assaulted her again with a tree branch in the woods — which he left inside her when he abandoned her body — and then slit her throat.

Colleen Ritzer's Funeral

WENN Rights Ltd / Alamy Stock PhotoFamily, students, and fellow teachers gathered to mourn Colleen Ritzer on Oct. 28, 2013.

At Chism’s trial, Essex County Assistant District Attorney Kate MacDougall said that Ritzer’s body had been “stripped, battered, brutalized, and violated.”

“He had a goal,” MacDougall told jurors. “A terrible, terrible purpose. And he played it out in the woods and he didn’t care what came after that.”

Authorities determined that immediately after killing Colleen Ritzer, Chism had gone to the movie theater to watch a Woody Allen film and shoplifted a knife from a BJ’s Wholesale Club.

Philip Chism

ZUMA Press, Inc. / Alamy Stock PhotoPhilip Chism at his arraignment in October 2013.

Chism’s attorney, Denise Regan, argued that this chilling behavior was due to Chism’s severe mental illness. He was purportedly suffering a psychotic episode and hearing voices at the time of the murder.

“When Philip Chism followed Ms. Ritzer into that bathroom, he was not himself. He was not a kind, smart 14-year-old boy. He was responding to terrible command hallucinations in his head. He didn’t choose to do this.”

Jurors didn’t buy this defense, however. Philip Chism was convicted of murder, rape, and armed robbery and sentenced to life in prison with the possibility of parole after 40 years.

Hoping to celebrate their daughter’s life despite her tragic death, Colleen Ritzer’s family created a scholarship in her memory. One year after Ritzer’s murder, they released a statement marking the occasion. “Colleen was good, kind, and loving,” they wrote. “She was passionate about teaching and loved the life that she worked so hard to achieve.”

“We are grateful that her legacy lives on in a new generation of caring and passionate teachers through the recipients of Colleen’s scholarship,” the statement continued. “We continue to receive messages from those moved by Colleen’s passion for teaching, many of whom have chosen to become teachers themselves because of her inspiration. We are grateful to all who continue to keep Colleen’s legacy alive, a legacy of a caring teacher who was always good to people.”

After reading about the tragic murder of Colleen Ritzer, learn about Alyssa Bustamante, the teen who killed her nine-year-old neighbor. Then, go inside the story of Christa McAuliffe, the teacher who died when the Challenger exploded.

Marco Margaritoff
A former staff writer for All That’s Interesting, Marco Margaritoff holds dual Bachelor's degrees from Pace University and a Master's in journalism from New York University. He has published work at People, VICE, Complex, and serves as a staff reporter at HuffPost.
John Kuroski
John Kuroski is the editorial director of All That's Interesting. He graduated from New York University with a degree in history, earning a place in the Phi Alpha Theta honor society for history students. An editor at All That's Interesting since 2015, his areas of interest include modern history and true crime.
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Margaritoff, Marco. "Colleen Ritzer, The Math Teacher Who Was Killed After School By Her Ninth-Grade Student.", April 14, 2024, Accessed June 22, 2024.