The following is from the Dallas Morning News website and is pretty well right on with how this went down:
About 6 p.m. Tuesday, Smith and about six other gang-unit officers went to the Oak Wood Place Apartments to arrest Jobe.
Smith, flanked by two other officers, approached the door and knocked. Someone inside asked who was there, and Smith responded with a fake name, police officials said.
When the suspected gunman opened the door, Smith yelled that they were the police, according to the preliminary investigation. The suspect then tried to close the door, and Smith pushed back. That's when he was shot.
Officers returned fire, frantically trying to pull their fallen comrade out of the line of fire as the gunman opened the door and continued shooting. No one else was injured in the gunbattle.