No,but you find out she's part of the LCPD. Golden Eagle 007$$$
If you are talking about LCPD:FR or Police Pursuit Mod, then no. The Xbox 360 and PS3 are unmoddable. If you'd like to be a Police Officer in GTA IV then buy the PC version. :-)
It is possible to get a military helicopter (Annihilator) from the airport. It is also possible to get a normal LCPD chopper (Maverick) from on top of one of the LCPD buildings in Algonquin
No, Niko Bellic cannot join the LCPD in GTA 4.
You cannot become a real LCPD Officer on GTA IV.
yes
Yes But No Parachute.
NO! never!
Yes
Under the bridge
Annihilator
no, it's the police force in the game.