Can You Get GTA IV LCPD Mod on PS3?

Impossible. "LCPD" (Los Santos Police Department / Liberty City Police Department) is a PC mod for GTA IV adding LAPD/NYPD-inspired police content, vehicles, and missions. It's not an official game or DLC.

The PS3 does not support user-created mods—consoles run games exactly as developers released them, with no modification capability.

On PS3, you can role-play as police within base GTA IV multiplayer, but you won't have any LCPD mod features.