The guards were not injured. They called the Houston Police Department and Ofc. G.T. Clark responded.
As the guards were telling Clark their story, police said Hernandez drove by in a maroon Lincoln, but he fled when he saw the officer.
Clark chased Hernandez, who lost control of his vehicle in the 1600 block of Dunaway.
Police said Hernandez got out of his car, wielding a rifle that he pointed at Clark.
The officer told the man to drop the weapon, but the suspect refused. Officials said Clark fired at the suspect, who then fled into a nearby wooded area.
Police don't believe the suspect was injured.
Investigators recovered the rifle at the scene, but Hernandez hasn't been seen since.
The incident is being investigated by HPD's homicide and internal affairs divisions, as well as the Harris County District Attorney's office, which is routine procedure for officer-involved shootings.
Anyone with information that may be helpful to this investigation is urged to call HPD Homicide Division at 713-308-3600 or Crime Stoppers at 713-222-TIPS.