The jury made the decision on Tuesday, increasing the man’s charges from second- to first-degree murder, the Sun Sentinel reports.
Harrouff is accused of killing John Stevens, 59, and his 53-year-old wife, Michelle Mishcon in the garage and driveway of their Tequesta, Florida, home on Aug. 15.
When law enforcement arrived at the scene, they allegedly found Harrouff trying to bite off chunks of Stevens’ face.
The Martin County grand jury formally charged Harrouff with the murder counts along with counts of attempted murder and burglary, CBS News reports.
According to Fox News, the indictment allows prosecutors to seek the death penalty against Harrouff.
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Harrouff allegedly left a restaurant where he was dining with family, turned down the couple’s street and killed them in a “random” and unprovoked” attack, Martin County Sheriff William Snyder previously told PEOPLE.
Police documents released earlier this month alleged Harrouff pleaded with responding officers to kill him on the night of the murders and confessed to eating “humans.”
“Kill me, [expletive] kill me! Shoot me now! I deserve to die!” the teen allegedly told Martin County sheriff’s deputies after they pulled him off of John Stevens’ lifeless body, according to documents obtained by PEOPLE.
When asked what he ate, Harrouff allegedly told officers, “Humans,” according to WPTV.
It allegedly took multiple officers and a police dog to get Harrouff off of Stevens, and in the new police documents, deputies allege they saw Harrouff spitting out human flesh.
Harrouff was formally charged on Oct. 3 with with two counts of murder and one count of attempted murder.
Snyder initially speculated that Harrouff may have been under the influence of the synthetic drug flakka during his alleged attack, but the results from a subsequent toxicology report have not yet been announced. Harrouff’s father has previously said schizophrenia runs in his family.
It is unclear whether Harrouff has entered a plea and his defense attorney did not immediately respond to PEOPLE’s request for comment.