James Cervera, the Virginia Beach Chief of Police, said officers in the department had a training on how to handle "large-scale events," such as mass shootings, just weeks before last night's deadly attack.

"As recent as March 30, we had a large-scale training event, which incorporated not only police, but our colleagues in fire and EMS and sheriff's department to be able to respond to a large-scale event, such as this," he said.

He said that while training is important to establish protocols "everything changes" during real events.

"While we train extensively, while we go over all of our protocols extensively, once you enter an environment such as this, everything changes. Things change in a moment's notice, such as the gun battle with the suspect. So we did train as recent as March 30, but officers had to make instantaneous decisions at that moment in time on how to engage the suspect.