If today you find yourself simultaneously defending the rights of gun owners, gays, and Muslims, you just might be a libertarian.
Banning Muslim immigration wouldn't have stopped this heinous crime, since the shooter was born in America. Giving in to blind collectivist hatred against innocent minorities would validate the shooter's position, who likely was a murderous, bigoted homophobe. That is where hatred ends, and we should not encourage it by emulating it.
My pro life stance is based around the idea that the unborn is a human child, and that all humans deserve the same rights to life, liberty, and the pursuit of happiness.