TULSA, Oklahoma - A Tulsa man is in jail after police say he sexually assaulted a teenage girl at a midtown apartment complex. Calvin Hill was also booked on four complaints of knowingly spreading an infectious disease.

Police were called to the Canyon Creek Apartments at 2053 East 51st Street after a 16-year-old girl called to say she'd been raped.

Sex crime detectives say the girl had been in a consensual relationship with Hill, but that he assaulted her Tuesday morning after a confrontation.

“She says he forced her down on to an air mattress and sexually assaulted her,” said Tulsa Police Sergeant, Mark Mears.

Mears said the girl claimed Hill put her phone in water to keep her from reporting the crime, but once she got away, Mears said the victim did the right thing and called 911.

Police say Hill was sitting outside on a staircase. When questioned, he denied the assault, according to police.

According to an arrest report, Hill told investigators he found out he was HIV positive in October.

Mears said Hill told detectives he and the victim had consensual sex three other times, but he had never told the girl about the disease.

“He knew he had it and he had intercourse with her. He didn't give her any warning and the results of that are obvious, or the potential results are obvious,” Mears said.

Hill is facing four counts of knowingly intending to transfer HIV. It's a crime Mears said is uncommon, but not unheard of; something he said can mark the victims for life.

“I know that the treatments have progressed a great deal, but she still would have to be dealing with that for the rest of her life,” he said.

Hill's mother defended her son and said she doesn't believe the accusations.

She said her son has been private about being HIV positive, but doesn't think he would mislead anyone, especially a sexual partner, about the disease.

Hill's mother also said she doesn't have bail money, so Hill will be staying in jail for now.

He is being held on a $120,000 bond.