YNW Melly may fry for killing his YNW crewmates Sakchaser and Juvy.

Documents revealed to TMZ show that the state of Florida plans to seek the death penalty in the double murder, which they allege Melly set up to look like a driveby.  They refer to Melly as a "criminal gang member" in the documents.

Prosecutors also plan to use Melly's lyrics -- specifically the bars in his biggest hit "Murder On My Mind" -- against him in court.

Melly pleaded not guilty last month and remains locked up without bail. He's spoken about a violent alter-ego named Melvin in the past, and that may be part of a mental illness defense.