Updated

The gunman who killed five Dallas police officers did not have a large stockpile of bomb-making materials at his suburban home, two officials said Friday, contradicting earlier claims that Micah Johnson possessed enough explosives to stage a larger attack.

Officers who searched Micah Johnson's home Friday found small amounts of an explosive known as Tannerite, as well as acetone, which can be used as an accelerant in explosives, according to the officials, who are familiar with the investigation. They spoke to The Associated Press on condition of anonymity because they were not authorized to discuss the case publicly.

Both Tannerite and acetone are legal and easy to purchase. Tannerite is often found in small targets that emit powder when hit by a gunshot, such as those at gun ranges. Acetone is commonly sold as nail polish remover.

In greater quantities, Tannerite can be used to create large explosions. An advisory posted online by the company that manufactures it says its intended use is around 1 pound. The company sells targets with half-pound and 1-pound quantities. At 50 pounds, the advisory says, Tannerite can be used as an "exploding target" with another chemical additive.

An FBI intelligence bulletin from 2013 warns that Tannerite and other exploding targets can be used with other materials to make explosives. Tannerite consists primarily of ammonium nitrate, a common ingredient in fertilizer that has been used in attacks, mixed with aluminum powder.

After the July 7 attack, Dallas Police Chief David Brown repeatedly said Johnson had enough explosives on hand to do far greater damage.

"There was a large stockpile," Brown told reporters Monday. "One of the bomb techs called me at home to describe his concern of how large a stockpile of bomb-making materials he had. And according to that bomb tech, he knew what he was doing, and this wasn't some novice."

A day earlier, Brown told CNN that the materials in Johnson's home were "large enough to have devastating effects throughout our city and our North Texas area."

A police spokesman declined to comment.

Brown said Johnson told police he had planted bombs as part of his assault on officers to protest recent police shootings of black men. He told authorities he was targeting white officers. In addition to the five officers who were slain, nine others were wounded, along with two civilians.

Police killed Johnson with a bomb delivered by a remote-controlled robot.