THE Matthew Shepard and James Byrd Jr. Hate Crimes Prevention Act, which President Obama plans to sign soon, is named after two men who were murdered in 1998. Shepard, a gay college student, was beaten to death in Wyoming. Byrd, a black hitchhiker, was dragged to death behind a pickup truck in Texas. Bigotry seemed to play a role in both crimes. Here is something else Matthew Shepard and James Byrd have in common: Their killers were arrested, tried, convicted and sentenced to life in prison or death -- all without the benefit of hate-crime laws, state or federal.