TULSA, Oklahoma - A Tulsa teenager is in jail after police said he sexually assaulted a young family member. 

Tulsa Police identified the suspect as 16-year-old Darius Ferguson and they said this is not the first time he's been arrested for a sex crime.

Tulsa police said they want to bring justice to Darius Ferguson's 4-year-old victim.

Officers were called Thursday night to an apartment complex near 31st and Sheridan to investigate a report that a child had been sexually assaulted.

"They interviewed the 16-year-old who admitted to in fact sexually assaulting the four-year-old," said Mark Kraft with Tulsa PD’s Child Crisis Unit.

Police said the child was left at another family member's apartment, where Ferguson also lives.

They said that's where the abuse happened.

They also said the child's mother called police after he told her about being abused.

"When she went to pick the child up, he disclosed to her that he had been sexually assaulted and she called us," said Kraft.  

Police arrested Ferguson on a complaint of first-degree rape. 

Investigators say Ferguson was charged two years ago when he was 14, after admitting to sexually assaulting another family member who was 5-years-old.  

"We see a lot of bad stuff, and obviously we can’t change what happened but we just kind of hold onto the goal of preventing it from happening and keeping it from happening again," Kraft said. 

Darius Ferguson is being held at the Tulsa County Jail as he will be charged as an adult on the rape charge.