Nassau County is getting new equipment to prepare officers for if they have to respond to an active shooting incident.

Nassau police announced Thursday that they have acquired 150 semi-automatic weapons. In light of the number of mass shootings and acts of terror in recent weeks, officials said the weapons are a necessary addition.

"Approximately one-third of all active shooters in this country over the last several years used long weapons," said Acting Police Commissioner Thomas Krumpter. "It was quite clear that we had to increase the capabilities of the members of this department."

Krumpter said the rifles - each costing $1,100 - will be given to members of the department's special operations units, as well as select officers on routine patrol.

He said each officer will go through three days of training. They will then be given five 30-round magazines.

Officials said responding officers will no longer have to wait for tactical SWAT teams to take action.

"The longer we wait, the more people that are going to die," said Krumpter.

Officers will begin their training Friday morning.