Jonathan Cruz is accused of carrying out a killing spree based on a horror movie about murder being legal for one day a year.
A US prosecutor is seeking the death penalty for a teenager charged with fatally shooting three people over four days in May.
Terry Curry said 19-year-old Jonathan Cruz murdered the trio "for sport," and based the killing spree on the horror movie The Purge, which is about one day a year when murder is legal.
His actions were described by Mr Curry as "beyond senseless."
Cruz, from Indianapolis, Indiana, has pleaded not guilty to shooting dead Billy Boyd and Jay Higginbotham on 12 May, and Jose Ruiz three days later.
According to court documents, detectives said a witness told them Cruz confessed he had been "purging" by shooting and robbing people.
Police also believe he kidnapped a woman at gunpoint, and the woman told them Cruz was killing and robbing his victims.
Cruz picked his victims at random, the court heard, and sent text messages that made reference to the "Purge" series of movies.
He was arrested on 16 May.
The charges against him include murder, attempted robbery, armed robbery and criminal gang enhancement.
"Quite simply, we allege that these were killings for sport and could not be more appropriate for consideration for capital punishment," Mr Curry said.
The prosecutor added that he met the families of the victims and consulted defence counsel before deciding to pursue the death penalty.
Police Chief Troy Riggs said officers thought the case felt "different" when they first began investigating it, and he believed there may have been more victims if Cruz had not been caught.
Police Chief Troy Riggs said officers thought the case felt "different" when they first began investigating it, and he believed there may have been more victims if Cruz had not been caught.
