Download link for the new version of this mod available at gtaforums discuss page.

New version 1.1: Police weapons for all III era games but now each and every law member has his own weapon. Take a look:

San Andreas primary weapons from wanted level:
Cops from LSPD, SFPD and LVPD copcar:
 - driver - desert_eagle
 - passenger - pistol silencer
Cops from ranger (cop rancher car):
 - driver - pistol silencer
 - passenger - shotgun
SWAT units from the enforcer van:
 - driver - AK47
 - front right seat passenger - MP5LNG
 - rear left seat passenger - M4
 - rear right seat passenger - shotgun
FBI agents from the fbirancher:
 - driver - AK47
 - front right seat passenger - shotgun
 - rear left seat passenger - M4
 - rear right seat passenger - c*ntgun
Soldiers from barracks truck:
 - driver - AK47
 - passenger - combat shotgun
Soldier from tank (rhino):
 - single driver - combat shotgun

There's more - secondary weapons:
Cops from LSPD, SFPD and LVPD copcar - nitestick
Cops from ranger (cop rancher car) - nitestick
SWAT units from the enforcer van:
 - driver - pistol silencer
 - front right seat passenger colt45 pistol
 - rear left seat passenger desert_eagle
 - rear right seat passenger pistol silencer
FBI agents from the fbirancher:
 - driver pistol silencer
 - front right seat passenger colt45 pistol
 - rear left seat passenger desert_eagle
 - rear right seat passenger pistol silencer
Soldiers from barracks truck desert_eagle + bomb
Soldier from tank (rhino) desert_eagle + bomb

Ground teams:
SWAT Everyone have MP5LNG + teargas
FBI Everyone have AK47 + colt45
ARMY Everyone have M4 + Desert Eagle + Bomb

Helicopter teams:
4 SWAT members have 4 diferent guns:
AK47, MP5LNG, Shotgun, M4 (teargas is a secondary weapon).

Vice City primary weapons from wanted level:
Cops from copcar:
 - driver colt45
 - passenger python
Vice cops from police cheetah:
 - driver tec9
 - passenger ingramsl
SWAT units from the enforcer van:
 - driver mp5lng
 - front right seat passenger chromegun (shotgun1)
 - rear left seat passenger ruger
 - rear right seat passenger uzi
FBI agents from the fbirancher:
 - driver ruger
 - front right seat passenger chromegun (shotgun1)
 - rear left seat passenger mp5lng
 - rear right seat passenger m4
Soldiers from barracks truck:
 - driver m4
 - passenger SPAS (combat shotgun)
Soldiers from tank (rhino):
 - driver m60
 - passenger SPAS (combat shotgun)

Secondary weapons:
Cops from copcar nitestick
Vice cops from police cheetah colt45
SWAT units from the enforcer van colt45
FBI agents from the fbirancher python
Soldiers from barracks truck colt45 + bomb
Soldier from tank (rhino) python + bomb

For helicopter teams use my helicopter mod ("SWAT in the air").
For ground teams use the original version of this mod (1.0).

gta3 primary weapons from wanted level:
Cops from copcar:
 - driver colt45
 - passenger uzi (2 stars or higher)
SWAT units from the enforcer van:
 - driver uzi
 - front right seat passenger shotgun
 - rear left seat passenger ak47
 - rear right seat passenger m16
FBI agents from the fbi car:
 - driver uzi
 - front right seat passenger shotgun
 - rear left seat passenger ak47
 - rear right seat passenger m16
Soldiers from barracks truck:
 - driver ak47
 - passenger m16
Soldiers from tank (rhino):
 - driver m16
 - passenger shotgun

Secondary weapons:
Cops from copcar bat
SWAT units from the enforcer van colt45
FBI agents from the fbirancher colt45
Soldiers from barracks truck colt45 + bomb
Soldier from tank (rhino) colt45 + bomb

For ground teams use the original version (1.0).

Install: For SA you must have CLEO 4 installed. After CLEO is installed extract from SA folder to CLEO folder (of SA). Same thing for VC and III (don't mix SA, VC or III CLEO directories when extracting the files - otherwise the game will crash - obviosly).

Credits: For VC - passenger and driver pointers recovered by a coder named towncivilian in 2011. Everything else in this new version was made pretty much without the usage of memory addresses.