Updated

An Indianapolis man who justified his four-day killing spree with the horror movie "The Purge" was sentenced Thursday to spend the rest of his life behind bars.

Johnathan Cruz, 20, was sentenced to three consecutive life sentences without parole, with an additional 16 years in prison for armed robbery. He pleaded guilty to three counts of murder last month. Prosecutors dropped plans to seek the death penalty.

Cruz was charged with shooting and killing three men — Billy Boyd, Jay Higginbotham and Jose Alberto Ruiz — between May 12 and May 15, 2016. Prosecutors claimed he "killed for the sport" and the attacks were "absolutely random," Fox 59 Indianapolis reported.

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Witnesses said Cruz confessed he'd been "purging" by shooting and robbing people, according to detectives. He allegedly posted one message that said, "I purge every night now," and kept videos of shootings and gang activities on his phone.

He justified the murders by referring to the 2013 movie about a night in a year when people were allowed to commit violent crimes.

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