(CNN) Ever since the days of the old "CHiPs" TV show, motorcycle officers have maintained a certain look of cool. Flashy bikes, funky helmets, cool shades.

If you happen to be in Tempe, Arizona, you'll notice something new adorning the bike cops ensemble as they whiz by: AR-15s.

The Tempe Police Department added the high-power rifles to the back of eight motorcycle units about six months ago, and yeah, they've gotten some stares.

"People do notice. We've had both sides. We've had people concerned about how it looks. It looks militaristic," Sgt. Ronald Elcock of the Tempe Police Department told CNN affiliate KPHO. (CNN has reached out to the department for comment and is waiting to hear back.)

The department said cops on motorcycles can often be the first officers to respond to a crime scene. So, it wants to make sure the officers have enough firepower to deal with whatever situation they may be riding into.

Elcock says each bike officer goes through 40 additional hours of training before being issued a rifle, and the guns stay locked with a special mechanism that only the officer can open.

"So it's not something that anybody can go up there and grab off the back of the motorcycle," he told the affiliate.

But motorcycle officers aren't the only officers with the weapons in Tempe. The police department has more than 100 AR-15s, used by both regular patrol officers and the SWAT team.

Many other departments around the nation also give officers the rifle.