MISHAWAKA, Ind. – A 16-year-old Indiana high school football player is expected to be formally charged with murder Monday after the body of one of his classmates, a 17-year-old pregnant cheerleader, was found in a dumpster during the weekend, officials say.

Aaron Trejo is currently being held on a preliminary murder charge following his arrest Sunday, the St. Joseph County prosecutor’s office told the Associated Press. Moreover, he will be tried as an adult, reported Fox News.

pregnant cheerleader

Aaron Trejo, is expected to be formally charged with murder in the death of Breana Rouhselang. (St. Joseph County Police Department)

Breana Rouhselang, a Mishawaka High School student, was last seen alive at her home at around midnight Saturday. Her family called police about 4:30 a.m. Sunday after they “got the feeling that something wasn’t right,” said Lt. Alex Arendt of the St. Joseph County Metro Homicide Unit.

Their premonition proved correct. Hours later her body was discovered in a restaurant dumpster nearby, police said. Arendt says Rouhselang knew Trejo from the football team, but the extent of their relationship was unknown, and is a key focus of the investigation.

Rouhselang had been a softball coach, a cheerleader and football team manager at the school, the girl’s stepmother, Nicole Rouhselang, told reporters Sunday. Furthermore, she said her stepdaughter had been about six months pregnant.

“I’ve known her since she was 6,” she said. “I just don’t understand it.”

The report did not indicate who the father might be.

Police haven’t released details about a possible motive. Consequently, an autopsy was planned to determine the cause of death.

The school district in Mishawaka, which is next to South Bend and about 80 miles east of Chicago, issued a statement Sunday saying administrators were working with authorities in investigating the “terrible tragedy” and that grief counselors would be available at Mishawaka High School on Monday.

“Our thoughts and prayers are with the family members and friends who have been affected by this great loss,” the statement said.

Students at the school walked out around 11 a.m. local time Monday – the time 24 hours earlier when her body was discovered – to observe a moment of silence, according to ABC 57.