(Reuters) - A 16-year-old Indiana boy, who police say confessed to killing a classmate who was carrying his baby, was charged on Monday with murder and feticide, prosecutors said.

Aaron Trejo, 16, charged with murder and feticide in the death of 17-year old Breana Rouhselang, appears in a booking photo provided by the St. Joseph County Prosecutor's Office in South Bend, Indiana, U.S. December 10, 2018. St. Joseph County Prosecutor's Office/Handout via REUTERS

The charges came a day after Aaron Trejo was arrested for the death of 17-year-old Breana Rouhselang, whose body was found in a South Bend, Indiana dumpster on Sunday, partially covered by a trash bag.

Rouhselang had been stabbed and strangled to death.

Trejo, who initially denied involvement in Rouhselang’s disappearance, later confessed to killing the girl because she had not told him about the pregnancy until it was too late to abort the baby, a South Bend police detective said in court documents.

“I took action .. I took her life,” Trejo said, according to South Bend Police Detective Gery Mullins.

Rouhselang, who was six months pregnant, was reported missing by her family on Sunday after failing to return from a late-night meeting with Trejo behind her house, Mullins said in the affidavit.

Trejo and Rouhselang met at Mishawaka High School in the South Bend suburb of the same name, where Trejo played on the football team and Rouhselang was team manager.

The high school called Rouhselang’s death “a terrible tragedy” in a statement posted on its website.

According to the affidavit, Trejo told police that he had been planning to kill Rouhselang and the baby for about a week and stabbed her with a knife he had brought from home. He then threw the knife and her phone into a river.

An autopsy found that the victim died from multiple stab wounds and strangulation by her scarf, the affidavit said.

Trejo’s family members could not be reached for comment on Monday and it was not clear if he had retained a criminal defense attorney.