The man who shot dead five police officers in Dallas and wounded seven more was planning an even larger attack, the city’s police chief says.
Micah Johnson, 25, was angry with the recent killings of black men by police and wanted to kill white officers, police say.
Police chief David Brown said he was “convinced” Johnson had wider plans.
He told CNN that Johnson, a military veteran, appeared to have practised detonating explosives.
Mr Brown also said police were trying to find the significance of the letters “RB” that Johnson had written in his own blood, near where he was killed by a remote detonation by police.
Officers were also reading a journal found in Johnson’s house that Mr Brown said was proving “hard to decipher”.
Mr Brown also revealed that during two hours of negotiations last Thursday, the attacker taunted police.
“He just basically lied to us – playing games, laughing at us, singing, asking how many [police officers] did he get and that he wanted to kill some more and that there were bombs there.”
“So there was no progress on the negotiation… I began to feel that it was only at a split second he would charge us and take out many more before we could kill him,” Mr Brown added.