The bad guys literally won't hear the cops coming, if the Fremont, California police department has its way.

In an effort to make itself greener and, longer-term, leaner, the department has invested in an all-electric Tesla Model S (TSLA) - Get Report to replace an aging Dodge Charger cruiser.

The single Model S might be more expensive right off the bat, at just more than $61,000 plus the costs of converting it into a fully-fledged police cruiser, according to a press release. Modifications include a "light bar, push bumper, and ballistic barriers."

But savings in gas and maintenance could make it a lot cheaper for the department over five years of use - the average life cycle of such a vehicle. The Fremont Police Department has already installed a solar array on top of the Police Complex's carport to charge electric cars, including the new Tesla.

"The electric patrol vehicle pilot program is an extension of the City's clean technology and smart city initiatives to help make Fremont a more sustainable community," said Fremont Police Captain Sean Washington. "Given that Fremont Police vehicle fleet is responsible for a total of 980 metric tons of carbon dioxide emissions annually, this program has the potential to eliminate 10 percent of all municipal greenhouse gas emissions."

Fremont isn't the first city to buy Tesla vehicles for its police. Basel, Switzerland added seven Model X SUVs to its fleet in December, while Canada's Ontario Provincial Police also showed off a converted Model X pursuit vehicle at last year's Canadian International Autoshow.