Optical Enhancement

The snipers scope, may very well be the most important part of the weapon.
(Example): If you have a $3,000.00 Weapon and a $30.00 scope, you have a really expensive piece of crap. Many times the scope you place on the rifle may well be as expensive as the weapon itself.
The most widely used scopes are:

Carl Zeiss Scopes
Simmons
Unertil
Leupold Vari-XII 3x9x40
Tasco 8x40x56mm Scope with 1/8th" MOA, Image Enhanced, External Parallax (Yes, a Tasco)
Burris
Bausch & Lomb Elite Series
Swarovski Optik
Kahles (a Swarovski company)
Steiner Z Scopes
Nikon
Weaver
Schmidt & Bender Rifle Scopes

There are MANY different scopes on the market. Some with special features that take some getting used to. That is why I suggest using a scope that is:
1. Simple to operate
The more controls, the more the variables!

2. Sturdy
It WILL get banged up.

3. Constructed with quality
If it is made well, it will work well!

Don't let yourself get caught up in the incredible amount of "gagetry" that is out there.
Remember the rule: "K.I.S.S." Keep It Simple Sniper! (my own variation).

Finaly, if you are going to select a scope for your duty weapon, make sure you practice with that same weapon. Most departments require this, oddly enough some do not. It is important to practice only with your duty weapon, and not a "practice" weapon, to encourage repeatability. In doing this you can increase your shot consistency. Using the same weapon system for practice and duty increases confidence in the officers' shooting ability and reveals the limitations they may have.