The suspect, described by O'Neill as a 27-year-old career criminal, was shot multiple times and is listed as stable, O'Neill said. Multiple reports identify him as Christopher Ransom of Brooklyn.
Simonsen and Sgt. Matthew Gorman were working an unrelated case nearby when they responded to a call shortly after 6 p.m. "Through the windows of the store the officers did not see anyone inside".
A witness told the NYDN that before police arrived, one of the robbers, dressed in black, could be seen escorting two employees to the back of a T-Mobile store at gunpoint. When the suspect reached the front of the store, officers outside began to fire. "We have a total of seven members of the service who discharged a total of 42 rounds during this incident".
"He was definitely shot, he was limping then after that more cars came and there was more shooting", Jason Parodi said.
According to Maloney, Detective Simonsen was shot once in the chest and was not wearing a bulletproof vest. Maloney confirmed all shooting took place outside the store, to the left and right of the main entrance.
"You have to understand, this happens in seconds", Monahan said.
"This is an absolute tragedy, the worst outcome any police officer or family of a police officer could ever imagine", police commissioner O'Neill added.
Officers recovered an imitation firearm at the scene, believed to be what the suspect used in the robbery.
Both officers were rushed to Jamaica Hospital Medical Center where Simonsen was pronounced dead.
De Blasio said Wednesday all flags in the city would be lowered to half-staff to honor the slain officer.
O'Neill said a sergeant, who has been on the force for 8 and a half years, was also wounded and is in stable condition.
Mayor Bill de Blasio and several other city officials are at Jamaica Hospital Trauma Center.
De Blasio echoed the police commissioner's statements saying, "I want to just note how hard it is for our men and women in uniform to go into a situation like this one, to go into a situation where people's live are in danger, where there's someone with a weapon ready to recklessly use it at any moment and our officers, our detectives, our sergeants go in selflessly to protect others and they know it's a moment where they can not hesitate".
New York City police detective was shot and killed by friendly fire Tuesday night as officers confronted a robbery suspect who turned out to be armed with a replica handgun, Commissioner James O'Neill said.
As for the weapon he pointed at officers, police say it was a fake gun.