The lone gunman who killed six people in a random shooting at a Sikh temple in Oak Creek, Wisconsin has been described as a white, bald male in his 30s, sporting a 9/11 tattoo.
The police have not released further details either about the identity or weapon of the suspect, who eventually died in a shoot-out with police.
However the authorities have confirmed there was only one gunman - refuting early reports that the shooter may have had an accomplice.
While no motive has been established for the killings, it has been suggested that the gunman may have mistaken the Sikhs for Muslims.
The gunman is reported to have opened fire as soon as he entered the kitchen of the temple at around 10:30 am local time (16:30 BST) on 5 August, just before a large service took place.
While four people were killed inside the temple, three others, including the gunman, were killed outside.
The authorities have confirmed that the gunman ambushed and shot a police officer who was trying to help a victim. The officer, a 20-year veteran of the force, is undergoing treatment in hospital and is reportedly in a stable condition.
In addition to killing six temple-goers, the attack left a further three injured. All three are now in a critical condition in hospital.
Oak Creek police chief John Edwards said the authorities are treating the incident as a matter of domestic terrorism.
Teresa Carlson, the agent in charge of the FBI's Milwaukee division, added that "while the FBI is investigating whether this matter might be an act of domestic terrorism, no motive has been determined at this time."
The shooting comes less than a month after 12 people were killed by a masked gunman at a screening of Batman in Aurora, Colorado.
"The gunman is worse than the one at the [Aurora] theatre a couple of weeks ago because he targeted an entire community," Jagatjit Sidhu, who witnessed the Oak Creek shooting first hand, told Reuters.
"We never thought this could happen to our community. We never did anything wrong to anyone," Devendar Nagra told the Associated Press. Nagra's sister was at the temple during the attack, but managed to escape.
The authorities have started probing the suspect's house just a few miles from the temple, along with bomb squad specialists.
Support from President
US President Barack Obama expressed his condolences for the victims.
"Michelle and I were deeply saddened to learn of the shooting that tragically took so many lives in Wisconsin. At this difficult time, the people of Oak Creek must know that the American people have them in our thoughts and prayers, and our hearts go out to the families and friends of those who were killed and wounded," Obama said in a statement.
He promised to provide all the support needed for the victims and for the officials who are investigating the attack.
"The president said that he wanted to make sure that, as we denounce this senseless act of violence, we also underscore how much our country has been enriched by our Sikh community," said the White House statement.
Hundreds of people gathered in the evening for a candle-lit vigil for the victims of the incident.