An audio recording of the moment a police officer was shot multiple times by a suspected white supremacist has been released by US authorities.
Lieutenant Brian Murphy was the first officer on the scene of a gun attack at a Sikh place of worship in Oak Creek, Wisconsin.
Former US Army soldier Wade Michael Page opened fire with a 9mm handgun as dozens of people prepared for Sunday morning services.
Six people were killed and three critically wounded in the attack - including Lt Murphy as he went to the aid of one of the victims.
After arriving at the scene, he told the dispatcher: "I need an ambulance. I do not see a shooter anywhere...
"I have someone walking out the driveway towards me. Man with a gun, white t-shirt."
Moments later, gun shots can be heard on the recording, followed by silence.
The gunman was shot dead by a second officer as further support arrived on the scene.
The dispatcher said: "Subject with a gun, balding, white t-shirt. Officer down."
Lt Murphy was shot eight times and remains in a critical condition in Froedtert Hospital trauma centre.
Page, 40, was a failed soldier who played in white supremacist heavy metal bands with names such as Definite Hate and End Apathy.
He was a former US Army psychological operations specialist who served between April 1992 and October 1998, before he was discharged at Fort Bragg, North Carolina, for "patterns of misconduct".
The Southern Poverty Law Centre, a non-profit civil rights organisation, described him as a "frustrated neo-Nazi".
He wrote frequently on white supremacist websites, describing himself as a member of the "Hammerskins Nation" - a skinhead group rooted in Texas that has offshoots in Australia and Canada, according to the Maryland based intelligence firm SITE.
As a "psy-ops" specialist, Page would have trained to host public meetings between locals and American forces, use leaflet campaigns in a conflict zone or use loudspeakers to communicate with enemy soldiers.
He never deployed overseas in that role, Army spokesman George Wright said.
Special Agent Teresa Carlson, head of the FBI's Milwaukee field office, said Page was the subject of a "domestic terrorism" probe.
He said: "We are looking at ties to white supremacist groups. We did not have an investigation on him before yesterday.
"No law enforcement agency had any reason to believe he was plotting anything."
Online records show Page had a brief criminal history in other states, including pleading guilty to misdemeanour criminal mischief after a 1994 arrest in El Paso, Texas. He received six months' probation.
Page also pleaded guilty to driving under the influence in Colorado in 1999 but never completed a sentence that included alcohol treatment, records show.
He was arrested on suspicion of drunk driving again in 2010 in North Carolina after running his car off the side of a highway. The case was dropped a year later for lack of evidence, according to court records.