There's another delay in justice in the case of a Bronx teen who was stabbed to death in an unprovoked attack. Waldo Mejia was deemed not fit to stand trial on Wednesday. Mejia is charged with murder, manslaughter and criminal possession of a weapon, although he has not yet formally been read his charges. Police say Mejia is responsible for killing Caleb Rijos, 14 on Jan. 5. The teen was on his way to school when Mejia stabbed him multiple times in the chest in an unprovoked attack, according to investigators. Mejia was arrested on Jan. 11 but has not yet been arraigned as a judge questioned whether he was mentally fit to stand trial. A mental health evaluation was ordered during his last court date in February. His defense team will now have the chance to review the results of his evaluation ahead of his next court date. News 12 cameras were allowed in the court room as Mejia appeared to be expressionless and exchanged a few words with his attorney. Mejia is also being charged for a separate stabbing that happened at the 138th Street subway station just days before police say he attacked Rijos. The 29-year-old has violent criminal record, and history of mental heal issues. Rijos' mother previously spoke on News 12 about her push to get state laws passed that would prevent anyone accused of killing a minor from being allowed to claim mental illness as a first line of defense. Mejia is due back in court on March 20.