Troy Aikman is demanding justice for an SMU student who was shot and killed on Halloween ... with the Hall of Famer pleading with the public to come forward if they have any information on the case.
Dallas police in Texas say at around 3 a.m. on Saturday ... 19-year-old Robert “Jaden” Urrea was pronounced dead with a gunshot wound near bars in downtown.
Cops say in surveillance video of the incident ... they could see Urrea interacted with a white, 4-door car -- when suddenly the vehicle sped off and Urrea crumpled to the ground.