After a mental evaluation was ordered for murder suspect Juan Martínez Matos, a court-appointed psychiatrist has determined that the 26-year-old is not fit to stand trial.

Martínez Matos is charged with first-degree murder in the brutal killing of 19-year-old Jorge Steven López Mercado in Puerto Rico. He has also been charged with other counts, including weapons violations.

Psychiatrist Rafael Cabrera said the suspect should be kept in a forensic psychiatric hospital, according to the website Caribbean Business. Cabrera admitted, though, that the suspect may be faking or exaggerating his symptoms.

Judge Camila Jusino ordered Martínez Matos to undergo another evaluation on January 7 and set a new hearing on his fitness to face criminal proceedings for January 13.

According to police reports, López Mercado was dressed as a woman when Martínez Matos picked him up on a street known for prostitution in the town of Cayey. He claimed he didn't know López Mercado was a man and that he killed him in self-defense. López Mercado's body was found decapitated and partially burned alongside a road in central Puerto Rico November 13.