In opening statements Monday, Philip Chism’s defense attorneys admitted he killed and raped his 24-year-old math teacher Colleen Ritzer.

It was the first sentence of defense attorney Denise Regan’s opening statement.

“Philip Chism killed Colleen Ritzer and did unspeakable things to her body.”

Regan went on to lay the groundwork for an insanity defense. She said he had been diagnosed with a psychotic disorder – something he shared with his maternal grandmother and aunt. Regan pointed to how illogically Chism acted after Ritzer’s death, exposing his face to many cameras, walking around barefoot with bloody pants, and using Ritzer’s credit cards.

Chism, now 16, was 14 at the time of the crime.

In their opening statements, prosecutor Kate MacDougall meticulously recounted the details of the crime, minute by minute – the way Chism put on gloves before entering a bathroom to kill Ritzer, and had conversations with two friends he bumped into after her death. She told jurors prosecutors have no doubts that  Chism is guilt of first degree murder.

Colleen Ritzer’s mother takes the stand as a witness tomorrow.

Here, from The Associated Press, are snapshots from the trial as it developed.

12:40 p.m.

A police officer has told a jury that a teenager on trial for killing his math teacher told him about a girl buried in the woods.

Topsfield Officer Joseph DeBernardo testified Monday during the trial of Philip Chism in the 2013 killing of Danvers High School teacher Colleen Ritzer.

DeBernardo said he and another officer found a box cutter with blood on it in Chism's backpack. DeBernardo said when they asked whose blood it was, Chism said, "the girl's."

DeBernardo said when he asked Chism where the girl was, he said she was "buried in the woods."

"I asked him if we get to her, could we help her? He stated no," DeBernardo said.

Ritzer was stabbed with a box cutter and raped twice.

Chism's lawyer admitted during opening statements that her client killed Ritzer, but said he was severely mentally ill.


11:15 a.m.

A police officer has described finding a bloody box cutter inside the backpack of a Massachusetts teenager later charged with killing his high school math teacher.

Topsfield Officer Neal Hovey testified Monday as one of the first witnesses in Philip Chism's trial. Chism was 14 when Danvers High School teacher Colleen Ritzer was killed.

Hovey says he spotted Chism walking along a highway and brought him to a police station. He says inside Chism's backpack investigators found a bloody box cutter in a woman's wallet. Hovey testified that when he asked Chism whose blood it was, he replied, "It's the girl's."

Ritzer's body was found in the woods near the high school.

Now 16, Chism is being tried as an adult. His lawyer told jurors Monday that Chism killed Ritzer but that he was suffering from a psychotic disorder.


10 a.m.

A lawyer for the Massachusetts teenager charged with raping and killing his high school math teacher told a jury that he killed her and "did unspeakable things to her body."

Philip Chism was 14 when ninth-grade Danvers High School math teacher Colleen Ritzer was found near the school with her throat slit.

He is now 16 and being tried as an adult in Essex Superior Court in Salem.

Chism's lawyer, Denise Regan, began her opening statement Monday by telling the jury, "Philip Chism killed Colleen Ritzer."

Regan said Chism, who had moved to Massachusetts from Tennessee, was "severely mentally ill," and had suffered from a psychotic disorder since the age of 10.


9:30 a.m.

A prosecutor in the trial of a Massachusetts teenager charged with raping and killing his high school math teacher has told a jury that the boy went to school on the day she died with a "terrible purpose:" to kill his teacher.

During opening statements in the trial of Philip Chism, a prosecutor calmly described Chism's movements on Oct. 22, 2013. She said Chism came to school with a backpack containing a box cutter, gloves and a mask. She said Chism followed Colleen Ritzer into the girls' bathroom after school, then strangled her, cut her throat with the box cutter, raped and killed her.

Chism was 14 at the time. Now 16, he is being tried as an adult.

He has pleaded not guilty. His lawyer has indicated she will use an insanity defense.