Robert Allen has pleaded not guilty to the murder of XXXTentacion.

According to court documents obtained by Complex, the 22-year-old Fort Lauderdale resident entered the plea Tuesday, less than a week after he arrested on first-degree murder, robbery, and drug possession charges. Allen is one of four men who have been indicted in the fatal shooting of XXX, along with Michael Boatwright, Dedrick Williams, and at-large suspect Trayvon Newsome.

Boatwright and Williams have previously entered not guilty pleas; Boatwright, who is accused of firing the fatal shot, has been ordered to undergo a mental examination to determine whether or not he’s fit to stand trial. According to the order signed by Broward Circuit Judge Michael Usan, Boatwright must “be examined to determine whether the defendant has sufficient present ability to consult with his/her attorney with a reasonable degree of rational understanding, and whether he/she has a rational as well as factual understanding of the proceedings against him/her.”

It’s still unclear why the judge has raised these concerns.

XXX—born Jahseh Dwayne Ricardo Onfroy—was fatally shot June 18 outside a motorsport dealership in South Florida. Authorities say Boatwright and Newsome were both armed during the ambush; however, under Florida law, Allen and Newsome can also face murder charges for their alleged involvement.