The attorney for an off-duty suburban Dallas police officer who fatally shot a 16-year-old and wounded another juvenile said Tuesday that his client fired his gun because the officer feared for his life, but the attorney would not say whether either boy was armed.

Attorney Chris Livingston said Farmers Branch police officer Ken Johnson "fired his weapon because he felt in fear of his life and he felt that fear was justified." But Livingston would not provide specifics about what prompted the shooting Sunday evening.

Officials say after Johnson saw a vehicle being burglarized in his Farmers Branch apartment complex parking lot, he chased suspects as they fled. After the suspects' vehicle spun out about a half-mile away in Addison, an altercation led to the shooting.

Jose Raul Cruz was killed and the other juvenile, who also was shot, was hospitalized.

The Farmers Branch and Addison police chiefs said at a news conference Tuesday that many details won't be revealed until their investigations are complete, including whether either juvenile had a weapon. Addison police are investigating the shooting, while Farmers Branch police are investigating the initial encounter as well as personnel issues. The police chiefs met earlier in the day with the family of the teen who was killed.

"We will not rush this investigation," Farmers Branch police Chief Sid Fuller said, adding, "We're not being secretive, we're being thorough."

Addison police Chief Paul Spencer said officials believe there are witnesses who haven't come forward.

Johnson, who was not injured, is on paid administrative leave pending the completion of the investigations. Fuller said Johnson had no disciplinary record. He noted department policies do not allow off-duty officers to chase suspects in their own vehicles.

According to the Texas Commission on Law Enforcement, Johnson has worked for Farmers Branch police for a year. He worked as a peace officer for Dallas Area Rapid Transit for almost eight years before that.