A man accused of hurting twin children entered not guilty pleas during his arraignment Tuesday morning in Natrona County District Court.

Eric James Brown, 21, faces two counts of felony child abuse. He could spend up to 20 years in prison and have to pay $20,000 in fines if convicted on both charges.

Court documents say a Casper detective was called to an area emergency room on Sept. 8 to investigate after a doctor found signs of abuse on two children.

Both children were born in 2016. The Wyoming Department of Family Services was also called in to investigate.

Doctors reported bruising on both children. One child showed multiple bruises on the face, head, left shoulder, right forearm and right buttocks. The other child had bruising across her back, left elbow and left shoulder, as well as the hip and buttock area, according to the affidavit.

The mother's boyfriend, Brown, agreed to speak with a detective.

Throughout his interview, Brown reportedly said he noticed bruising and redness on the children but told the detective he thought they were from seat belts being too tight.

Brown also said he may have hurt one of the children accidentally while Brown was asleep, saying he was a heavy sleeper and has been told he moves a lot when he sleeps.

Brown reportedly said he may have held the children too tightly, grabbed them too hard or patted their backs too hard while burping them. He said he did not hurt them on purpose.

Court documents say Brown told a detective he gets frustrated. He reportedly said he never meant to hurt the children, but if he did, he was willing to take responsibility for what happened to them.

On Nov. 7, Brown's employer went to police and said she had some information about Brown.

She reportedly told a detective that she had been outside smoking with Brown when Brown allegedly said "Yeah, I did it. I probably shouldn't have pushed down so hard. I should not have been so rough with him."

The employer asked Brown what he did, and Brown reportedly admitted to hurting one of the children by being too rough, explaining that the child "just kept crying."

Court documents say at that point, the employer backed away from Brown and went into the store because she didn't want to hear any more.

Brown reportedly did not go into detail about what happened that day.

The employer told detectives that she had seen Brown get angry and become agitated at work, sometimes having to leave his post to go outside and smoke, according to the affidavit.

Judge Thomas Sullins on Tuesday denied a request from defense attorney Kurt Infanger to reduce Brown's bond from $20,000 cash or surety to $10,000.

Brown remains in custody.