Both the Endura and Delica are great choices for everyday cutting. The decision between them is usually based more on comfort with large/small blades more than anything else.
As a self-defense option... well, you're a police officer. Presumably you have a gun, a chemical mace or pepper spray, and a baton. What situations are you envisioning in which one or more of the above is not a better option? If you're out of everything except a knife, it's not likely to matter much what knife you've got, as long as it's sharp.
You might want to consider one of the Rescue models. The odds are good that someday you'll be first responder to a car or industrial accident where you need to carefully and quickly cut someone free from restraints.
As for carry: Pretty much every Spyderco knife has a lanyard hole. Braid a short lanyard on and remove the clip. Now you have a knife that rests at the bottom of a pocket, can be quickly accessed via the cord, and doesn't look like a knife to the general public.