Michelle Carter was convicted last year of involuntary manslaughter because she told her boyfriend to kill himself. She has now appealed this decision on grounds that her conduct was permissible under the First Amendment.

"Carter's words encouraging Roy's suicide, however distasteful to this Court, were protected speech," wrote her lawyers in a recently filed brief. "A criminal law that penalizes a person who encourages another person to commit suicide cannot survive strict scrutiny."

Carter wasn't present for the suicide of her boyfriend, Roy Conrad. But she communicated with him on the phone shortly before he attached a water pump to his car and poisoned himself with carbon monoxide. Carter had previously urged Conrad to go through with it, though her lawyers argue it was never definitively established that she egged him on at the very end, when he was actually taking the steps to kill himself.

She later told a friend that Conrad's suicide was her fault, though it's possible she just said that for attention. She is clearly a very disturbed person, as was Conrad.

But is she a killer? As I wrote in an op-ed for The New York Times a year ago, her conviction runs afoul of the First Amendment:

Ms. Carter's conduct was morally reprehensible. But—at least until today's ruling—it was clearly legal. While some states criminalize the act of convincing people to commit suicide, Massachusetts has no such law. Moreover, speech that is reckless, hateful and ill-willed nevertheless enjoys First Amendment protection. While the Supreme Court has carved out narrowly tailored exceptions for literal threats of violence and incitement to lawless action, telling someone they should kill themselves is not the same as holding a gun to their head and pulling the trigger. Nor is it akin to threatening to kill the president, which is specifically prohibited by law—and in any case, only considered a felony if done "knowingly and willfully." (Merely expressing hope that the president dies isn't enough.)… For decades, efforts have been underway to criminalize every obnoxious or problematic social interaction between K-12 kids in American schools. Hardly a week passes without a national news story about teenagers who were arrested on child pornography charges—and face unfathomably long prison sentences—because they had inappropriate pictures of classmates (or even themselves) on their phones. In Iowa, in June 2016, authorities tried to brand a 14-year-old girl as a sex offender for Snapchatting while wearing a sports bra and boy shorts. The following month, Minnesota police officers busted a 17-year-old for swapping consensual sexts with his 16-year-old girlfriend. Such matters should be handled by parents and teachers, not the cops. The same is true for the various issues that plagued Ms. Carter and Mr. Roy.

Carter is despicable. But defending free speech means protecting even vile expression from prosecution.