fort lauderdale fla. florida governor rick scott sign amend stand grind legislation friday make easy defendants state successfully claim protect commit violence previously law require defendants prove use force self-defense new law shift burden proof pretrial hear prosecutors rather defendants prove whether force use lawfully supporters stand grind laws include national rifle association powerful u.s. gun lobby see legislation bolster civilians right protect florida self-defense law initially pass 2005 inspire similar laws state remove legal responsibility retreat dangerous situation allow use deadly force person feel greatly threaten opponents say amend law embolden gun owners shoot first cite 2012 death unarm black teenager trayvon martin orlando area spur national protest black live matter movement neighborhood watchman kill george zimmerman acquit murder state stand grind law include jury instructions scott republican sign amend legislation law along spate measure pass week special session state legislature measure largely pass party-line vote legislature florida governor sign bolster 'stand grind law