Officers said they were called to the shooting just after 9 p.m. Sunday on Canal Street near West Hedrick in the Greater East End area.
When they arrived, officers found a man who had been shot, HPD said. He was taken to the hospital, where he died.
Investigators said that earlier that night, they got a call about a man roaming in a backyard in the same area. In that instance, officers arrived and found two men -- one in the backyard and another in the front.
Police said one of the men was arrested and the other was questioned and released. HPD Lt. J.P. Horelica said the man who was released was the one who was later found shot.
"When they arrived what they found was the victim that had been shot was the male that was released a few hours ago," Horelica said. "At this time, it's unknown if the two incidents are related, but it is the same male."
HPD said any suspect remains at large, and it's unclear what led up to the shooting.
Anyone with information is asked to call HPD at 713-308-8800 or Crime Stoppers at 713-222-TIPS.