I think telling them what you can offer at that immediate moment would get you into the police department faster than promising babes after the crisis which might never end. Sort of like how paper money might not buy you something in a z-poc but trading 100 rounds of ammunition still has value.
Tell them the truth: you are/were a Royal Canadian Army soldier and have combat experience. Even better if you show up with your own firearm. They'd be more likely to let you into their station knowing that rather than promising Kendra Wilkinson.