Resident Evil HD Remake Beat Lisa Trevor and get Barry's 44 Magnum gun

When you get to the final confrontation with Lisa Trevor, do not engage her unless you wish to save Barry. While you get a trophy for saving Barry, you stand to gain two trophies by not doing so. Do not return Barry's gun to him and allow him to die and you become eligible for the trophies: Every Woman for Herself (finish the game saving no one using Jill) and Starsenal (obtain and use all weapons in the game). If you do save Barry, you get the trophy "I'm a Member of S.T.A.R.S.".
It is not necessary to engage Lisa Trevor, simply fire a few shots to attract her attention (if attempting to save Barry) and then quickly shove the 4 stones over the edge.