After you get to lvl 38 it will only take 4000 exp to level up

When you go to the hole in the ground, after you fight eve for the first time,when the NYPD backup comes, do not go down the hole and exit the building.

Go to the cop on the far upright corner(the chubby cop)and keep talking to him because he gives you a couple of ammo clips.

NOTE:It may come handy in the sewers when you fight the monster(he's pretty hard for a beginner!)

When going to get the extra ammo in the nypd, go over to the other grey box (not on th desk), open it and you will get med. 3 every time you leave and enter the N.Y.P.D!!!!!!!