A southern New Jersey man who is in prison for killing a 6-year-old boy has admitted sexually assaulting a 2-year-old boy in a separate case.

Thirty-four-year-old Osvaldo Rivera pleaded guilty to sexual assault on Monday.

Under terms of the plea deal, Rivera faces 15 years in prison to be served concurrently with the 110-year sentence he is already facing after a jury found him guilty last year of the murder of the boy and the sexual assault of that boy's 12-year-old sister in September 2012.

The sexual assault of the younger child was the month before that.

The Camden County Prosecutor's Office said DNA evidence submitted to a state database helped link Rivera to the crime.