Maps in rotation for Metrocop HL2DM, but I guess you can figure out a use for them in GMod as well.
dm_metroplaza:
Mashup of the Trainstation Plaza exterior and interior with additionally accessible areas for that deathmatch fun, idea by papa @Mythos, with a special cameo by @Eastman.
dm_metroplaza2:
The Alyx standoff plaza map opened up a little for HL2DM action. See if you can figure out how to unlock the RPG!