TAMPA, Fla. — Florida Governor Rick Scott signed into law on Friday a controversial bill involving the state’s “stand your ground” self-defense rules, making it legal in some circumstances to fire a warning shot.

The law, which takes effect immediately, was inspired in part by the public outcry over the case of a black woman sentenced to a 20-year prison term under the state’s mandatory-minimum sentencing guidelines because she fired a gun at her abusive husband during an argument.

Marissa Alexander’s case drew comparisons to the acquittal last year of George Zimmerman, who argued he acted in self-defense in shooting and killing a black, unarmed teenager, Trayvon Martin.

Anticipating the new law, a judge recently delayed a retrial for Alexander, whose conviction was overturned on appeal.

Under Florida’s “stand your ground” law, people who use deadly force to defend themselves — rather than retreating to avoid confrontation — can be immune from prosecution if they have a reasonable fear of serious injury.