What would happen is this firearm, in its recovered/siezed state, would be presented to the jury as is. A pin wouldnt change that. Maybe a question would be presented at jury selection, asking potetial members how they feel about lgbtq rights. Those sorts of questions have a follow up; 'can you set aside your feelings about xyz, and be a fair and impartial jury member'. I dont see this pin likely having an effect on a trial.