An Indiana teenager who was convicted of smothering his two younger siblings to death on two separate occasions has now been sentenced to a combined 100 years in prison. 

Nickalas Kedrowitz was 13 years old when his 11-month-old stepbrother, Nathaniel Ritz, and 1-year-old half-sister, Desiree McCartney, were killed in 2017. He was found guilty last year on two counts of murder.  

Ripley County Prosecutor Richard Hertel said Kedrowitz told detectives that he was "freeing his siblings from hell." 

Nickalas Kedrowitz received a combined 100-year prison sentence after being convicted of smothering his two young siblings.

Nickalas Kedrowitz received a combined 100-year prison sentence after being convicted of smothering his two young siblings. (Ripley County Sheriff’s Office )

INDIANA TEEN FOUND GUILTY OF SMOTHERING HIS YOUNG SIBLINGS 

"This wasn’t some sort of heat of passion, one killing and then minutes or hours or even days later, we’re talking months here, so we think that the consecutive part of the sentence was warranted and appropriate in this circumstance," Hertel told reporters after the sentencing hearing. 

Kedrowitz, who is now 17, will serve a pair of 50-year terms that will run one after the other, according to Fox19

The teen was arrested in August 2018 in the May 2017 killing of Desiree and the July 2017 killing of Nathaniel, both of whom were found unresponsive at the family’s home in Osgood, about 60 miles southeast of Indianapolis. 

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The coroner's office had determined both children were smothered. 

A judge ordered that Kedrowitz’s case be handled in adult court despite his attorney’s arguments that the teen has untreated mental health problems. 

Fox News’ Louis Casiano and the Associated Press contributed to this report.