Las Vegas police patrolling the valley are adding more firepower to their arsenal to fight crime.

Classes are already under way as patrol officers train using the Smith & Wesson MP-15 semiautomatic rifle.

The Metropolitan Police Department Fiscal Affairs Committee approved the donation of $145,800 for 136 assault-style rifles and associated equipment. The donations were made by public citizens, mostly in the gaming industry, to the Las Vegas Metropolitan Police Foundation, which purchased the rifles and contributed them to the Police Department, Sheriff Bill Young said.

Twenty patrol officers qualified on the rifle last week in the first class, police spokeswoman Carla Alston said. There are 24 officers taking classes this week, she said. The classes last 40 hours or a full work week for police officers.

Young said the rifles will go to patrol officers first. The rifles cost about $800 apiece, Alston said.

The donations were in response to the slaying of Sgt. Henry Prendes on Feb. 1, Young said. Prendes, 37, was gunned down by 21-year-old Amir Rashid Crump, near Durango Drive and Patrick Lane. Crump was armed with an assault-type rifle at the time. Crump was later killed by police after an ensuing gunbattle.

A total of $315,000 was donated to the foundation, the remainder of which is expected to be used to purchase more rifles.

"Unfortunately the bad guys are carrying around heavy artillery," Young said. "The days of the whistle and nightstick are well in the past."

There have been 15 officer involved shootings this year. That is four more than in all of 2005.