Police told ABC13 that the victim is a young Hispanic male.
The suspect is not in police custody, investigators said, but the person of interest Houston police want to talk to is 22-year-old Adrian Mondragon.
Police told Eyewitness News the victim and a woman were walking out of the theater when they were approached by a man. That man then shot the victim, killing him.
Police said the shooting was not random and that the three people knew one another.
Mondragon had a prior relationship with the woman, police said.
Authorities said there was no fight or incident inside the movie theater. An off-duty officer nearby responded to the scene.