Teen admits murder of cheerleader girlfriend who hid pregnancy from him

Cheerleader murdered for hiding baby. Photo / Supplied

A teenage boy has pleaded guilty to murdering his cheerleader girlfriend when she was six months pregnant with their child.

Aaron Trejo, 17, pleaded guilty to the shocking murder and feticide of 17-year-old Breana Rouhselang and their unborn baby on Wednesday as part of a plea deal hearing.

The high school football player from Indiana in the US was accused of stabbing Breana, killing her and the baby, last December when he was just 16, news.com.au reports.

The high school football player told police the two had argued about the pregnancy on the night of her death, according to Fox News, which obtained court documents citing details of the case.

Aaron Trejo, who was 16 at the time of the killing, has admitted stabbing Breana as part of a plea deal. Photo / Supplied

In the report Detective Gery Mullins wrote that Trejo told him "Breana waited too long to tell (him) about the pregnancy to get an abortion.

"I asked Aaron what he did about that, and he replied, 'I took action … I took her life'."

Trejo told Detective Mullins that he stabbed Breana in the heart with a knife because he thought it would kill her quickly.

Breana 'waited too long to tell him about the pregnancy', Trejo said. Photo / Supplied

Then he stuffed her body into a black plastic bag, tossed the bag into a trash bin behind a restaurant and threw her phone and the weapon into a river in Mishawaka, which is about 130 kilometres east of Chicago.

Trejo's aunt, Alexzaundra Patton-Manu, last year told The Daily Beast his parents and siblings were "in complete shock" after learning of the allegations against him.

The dumpster where Breana Rouhselang's body was found. Photo / Google Images

"This is not him," she said. "This is not his character."

After pleading guilty to the charges, Trejo faces up to 80 years in prison when he is sentenced on January 7, 2020.