The violent crime happened at an apartment in the 1300 block of Greens Parkway at about 4:40pm on April 17, 2013.
Police say a coworker went to the apartment to check on Cesar Jose Enriquez, 36, when he failed to show up for work. Finding the door open, the coworker went inside, saw blood on the walls of the bedroom and then called 911.
Officers found two men, a woman and a baby girl in a bedroom. All three adults suffered gunshot wounds to the head. The baby was unharmed, but was also transported to an area hospital where she was treated and released to family members.
Elizabeth Mayorga, 18, and Anthony Contreras, 18, were both pronounced dead at the scene. Enriquez was transported to Memorial Hermann Hospital where he was later pronounced dead.
Investigators believe at least one person, either Mayorga or Contreras, was an innocent bystander.
Priscilla Perez, Contreras' sister, said, "Hopefully someone does not go by another day with this burden, that guilt, that hopefully someone will come and speak and whatever they know, to just call."
At this time, there is no known description of a suspect or suspects. Anyone with information in this case is urged to contact the HPD Homicide Division at 713-308-3600 or Crime Stoppers at 713-222-TIPS.