Philadelphia police officials intend to review the death of a man who viciously attacked five people and then gunned down by nine officers who fired 109 shots at him.

Police Commissioner Richard Ross told news reporters on Friday that the number of rounds fired was unusual and suggested that “contagious gunfire” might have been the cause.

“In a very volatile situation, particularly with a number of officers present, if there is one officer who reacts quicker than the rest and fires—and this was in fact a very dangerous and volatile situation based on what they knew—other officers hear that gunfire, and they believe they are now under fire, and that they return fire,” Ross explained.

“Clearly, 109 rounds is a significant cause of concern, regardless of what the circumstances are," he added. "It is not an indictment of the police officers, but it may be a significant training issue we need to address.”

The commissioner said he didn’t know how many bullets him Christopher Sowell on Wednesday night, but that most of his wounds were to his lower body.

Police fatally shot Sowell after he had stabbed his 8-year-old son and the boy’s friend, and attacked three other people in the Cobbs Creek neighborhood.

Among those who were attacked was Sowell’s daughter, whom he choked, an elderly neighbor, whose throat he slashed, and a woman whom he punched.

All the victims were hospitalized. The three stabbing victims were said to be in critical condition.

The motive for Sowell’s violent spree hasn’t been reported.