For training purposes that is. No sense of having them patrolling around, or having their SWAT Teams kicking doors with guns with orange tips.  But what they are doing is sensible training-wise, as there's safety and costs savings with airsoft as compared to real bullets. For airsoft companies, they have to thank the national ammo shortage for pushing Police departments to rely on airsoft for training needs.

The cause of such ammo shortage is the high demand of ammo from gun enthusiasts who have been buying left and right and this shortage has been ongoing since the first tem of President Obama who many see as aiming to have more restrictive gun laws, ammo taxes, and other actions that they perceive will take away their 2nd Amendment rights.

With the efforts for new gun control laws, such as the recently failed to expand background checks, made the buying frenzy even more. Ammo manufacturers are having a hard time keeping up with demand. This caused for the Police forces to conserve their ammo and allocating them for on actual duties.

There is no debate nowadays that airsoft guns are a practical choice for training police forces, and saving the ammo for live firing exercises and real world needs. Airsoft guns are used in training scenarios, helping in the conservation of ammo as needed by the Police Departments.

The use BBs for some shooting exercises is much cost-effective than using live rounds coupled with the safety in the use of airsoft guns that replicate real weapons in terms of weight and features. Now it's just a matter of making airsoft as important component in the training programs of police forces, even if the ammo shortage eases up. For cost-conscious and practical police departments, making the choice of having airsoft for training is relatively easy.

Any volunteers on being the "robbers" in a simulated bank robbery? If the police needs some volunteer airsoft players for training scenarios, all they need to do is post in a local airsoft forum they won't run out of players who want to try out PolSim (Police Simulation) even if they're the bad guys in the scenarios.