A Florida college student accused of killing a couple and chewing on the dead man's face has been indicted on first-degree murder charges.

A Martin County grand jury formally charged 19-year-old Austin Harrouff on Tuesday with two murder counts, attempted murder and burglary.

Harrouff was initially charged with second-degree murder in the Aug. 15 attack on 59-year-old John Stevens, and his wife, 53-year-old Michelle Mishcon, outside their Tequesta home. The indictment enables prosecutors to seek the death penalty against Harrouff.

Deputies say they found the former high school football player and wrestler in his underwear, making animal noises and biting Stevens' face as he pinned his victim's body to the driveway. Authorities say Harrouff also stabbed a neighbor, 47-year-old Jeff Fisher, who tried to help the couple.