By Colin Packham
SYDNEY, May 24 (Reuters) - Australian police failed to respond quickly enough to the threat posed by a gunman responsible for a 16-hour siege at a Sydney cafe in 2014 in which three people dead including the hostage-taker were killed, a coroner said in a report on Wednesday.
While attributing blame for the deaths of Lindt Chocolate Cafe manager Tori Johnson and lawyer Katrina Dawson to gunman Man Haron Monis, New South Wales Coroner Michael Barnes said police should have acted promptly after Monis fired a warning shot.
Monis killed Johnson shortly after that.
Dawson was killed by fragments of a bullet fired by police after they stormed the cafe in the city's central business district 10 minutes after the gunman fired the warning shot.
Monis was killed by police fire.
"The 10 minutes that lapsed without decisive action by police was too long," Barnes said in a finding handed down after two years of testimony.
A spokesman for New South Wales police declined to make immediate comment but said police would hold a new conference later in the day.
The siege, which began on Dec. 15, 2014, was Australia's most deadly incident inspired by Islamic State militants.
Questions have been raised every since about the police strategy of "contain and negotiate" that saw the siege last for more than 16 hours.
While concluding the strategy was appropriate at the beginning, Barnes said the police had an incomplete picture of the threat posed by Manos and they placed too much emphasis on the advice of an psychologist, who was not an expert in acts of terror, and the incorrect belief that negotiations were progressing.
Barnes recommended authorities reconsider their response to such incidents.
"The outcome of the Lindt cafe siege suggests that contain and negotiate strategy needs to be more rigorously assessed in the context of terrorist incidents," Barnes said.
Australia, a staunch ally of the United States and its escalating action against Islamic State in Syria and Iraq, has been on high alert for attacks by home-grown militants returning from fighting in the Middle East or their supporters.