'Monster ' : Convicted child killer Osvaldo Rivera , 34 , Osvaldo Rivera , 34 , has pleaded guilty to sexually assaulting a 2-year-old boy . A southern New Jersey man who is in prison for killing a 6-year-old boy has admitted sexually assaulting a 2-year-old in a separate case . Osvaldo Rivera , 34 , pleaded guilty to sexual assault 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 of the murder of 6-year-old Dominick Andujar and the sexual assault of that boy 's 12-year-old sister , Amber in September 2012 . The sexual assault of the younger child , a 2-year-old boy , 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 . Rivera is scheduled to be sentenced in the toddler assault case April 17 . 'Rivera had to be held accountable for the crime he committed against this toddler , regardless of having been previously sentenced to life in prison in another case , ' Assistant Prosecutor Christine Shah told Philadelphia Inquirer . In July 2014 , a Camden jury found Osvaldo Rivera guilty of the murder of Dominick Andujar , as well as charges of attempted murder , aggravated sexual assault , burglary and weapons violations . Scroll down for video . Lifetime behind bars : Rivera ( left ) faces 15 years in prison to be served concurrently with the 110-year sentence he is already serving in the 2012 killing of six-year-old Dominick Andujar ( right ) Crocodile tears : Rivera , pictured here sobbing during his arraignment September 4 , 2012 , told police he was high when he broke into the Andujar family 's home in Camden and assaulted a 12-year-old girl . At around midnight on September 2 , 2012 , Rivera broke into the Andujar family 's home in Camden and attacked then 12-year-old Amber Andujar as she slept on the couch . Amber began to scream , which awoke 6-year-old Dominick - and he rushed to his sister 's aid . The small boy fought with the attacker and managed to free his sister in the process . Amber , who was bleeding after being slashed in the throat by Rivera , ran to a neighbor 's home to call for help . By the time police arrived on the scene , the brave 6-year-old boy was dead after having his throat slashed . Little hero : Dominick had his throat slashed by Rivera as he rushed to protect his big sister , Amber ( right ) from her assailant . Capture : Rivera was found hiding behind a mattress in a home in Camden after the attack . Defiant : Amber Andujar ( left ) survived despite having her throat cut so deeply that paramedics could see her vocal chords . Rivera fled the house after killing Dominick , and Amber was later seen running through the neighborhood , screaming for help while bleeding profusely from the throat . Emergency responders said the cuts were so deep they could see Amber 's vocal cords . She later helped officers locate her rapist by telling them he was known by the nickname ’ Popeye ’ and lived in a Camden apartment . Police tracked him down to an apartment in the city and found him hiding between an upturned mattress and the wall . According to investigators , during his questioning Rivera had revealed that he had smoked 'wet , ' a combination of marijuana and PCP , prior to the killing . During Rivera 's sentencing last December , a defiant Amber Andujar declared : 'Today I stand here as a survivor . Even though he took a part of me away , in the end , you did not win . '
Osvaldo Rivera , 34 , faces 15 years in prison to be served concurrently with the 110-year sentence he is already serving . Rivera was found guilty six-year-old of slashing the throat of last year Dominick Andujar after breaking into his family 's New Jersey home . The convict pleaded guilty to sexually assaulting a 2-year-old boy two months before the Camden home invasion .