WEST PHILADELPHIA (WPVI) -- In a press conference on Friday afternoon, Philadelphia Police Commissioner Richard Ross said the number of shots fired by officers during a deadly, police-involved shooting was of "serious concern."
"It is of serious concern to us the number of shots that were fired," Ross said.
Commissioner Ross revealed nine different officers fired a total of 109 rounds in front of two houses on Wednesday night.
Thirty-two-year-old Christopher Sowell, believed to have a gun, was shot and killed.
The commissioner said Sowell initially refused to take his hand from his pocket, then "doing so abruptly and then removing something from his pocket.
"We're still trying to figure out what that was at this point in time. Again, have not located a gun, so unfortunately there's nothing about the investigation that suggests it was a gun at this time, but we're still looking," Ross said.
At this point, Commissioner Ross thinks this might have been a case of something called "contagious fire" - in a high-stress situation, one officer fired first, others reacted.
"Other officers hear that gunfire, and they believe they are now under fire, and they return fire - in this case, firing multiple times. As I've said, 109 rounds that we've counted, thus far" said Ross.
Sowell was the suspect in a violent, bloody rampage that injured three children and two women.
Investigators believe he stabbed two of the children, including his own 8-year-old son, and tried to choke his teenage daughter.
Ross says the responding officers had every reason to believe that Sowell was armed with a gun when he reached into his pocket.
However, police have not yet recovered a gun from the scene.
They did find several weapons used to cut the victims.
Given the number of shots fired at the suspect by police, Ross said there may be, "a significant training issue the department needs to address."
The department is currently undergoing "reality-based" training to prepare officers for volatile situations. All officers involved with killing the suspect will be interviewed.
In the meantime, all victims injured in Wednesday night's attack remain hospitalized, but Ross said their conditions are improving.