Well in my city, where I said a 5 year tac or detective can make $100,000 a recruit in the academy makes $47,000.Just like between your town and my city you cannot compare.
Many towns issue a duty weapon and authorize certain off duty weapons.
My city an officer buys his own but can only choose from .38 spec., 9mm, .40 S&W and .45 ACP.
From any of these makers: Springfield, S&W, Ruger, Sig, Glock. Add Colt if you're talking .38 spec.
If your old you can carry a .38 revolver as a duty weapon, otherwise you carry a semi and you can have a .38 revolver as a backup or off duty weapon
Nationwide for those that issue currently the most popular round in .40 S&W and the most popular weapons are polymer in some form of DAO