Some motorcycles for the Tempe Police Department are now equipped with upright mounts for semi-automatic rifles.
Sergeant Ronald Elcock said the department tested the mounts last year and decided to install them on eight of its motorcycles.
In a high-risk situation, Elcock says motorcycles can usually get to a scene much quicker than patrol cars.
However, until now, motorcycle officers were only armed with handguns.
Elcock said that's been a growing problem, because criminals are using more high-powered rifles and weaponry.
"We don’t want to go into those situations where we aren’t able to keep the public safe,” said Elcock.
Even though the AR-15s are highly visible on the back of the motorcycles, Elcock says they are secured with special technology.
“There's a locking mechanism that would prevent anyone, except for the operator, to be able to get at the equipment,” said Alcock.
Some worry about the militaristic look of the AR-15s mounted on the back of the motorcycles.
“There are people that may be scared to see it,” said Elcock. "However when we explain to them the reason why we have it I think it puts them a little bit more at ease."