By Bill Mears
(CNN) -- The Supreme Court on Monday ruled in favor of a woman who was convicted of violating a chemical weapons treaty by attacking a rival in a love triangle.
The justices unanimously concluded the federal government overstepped its authority when prosecuting Carol Anne Bond of Pennsylvania. The decision sends the case back to lower courts, which could vacate the conviction.
"The global need to prevent chemical warfare does not require the federal government to reach into the kitchen cupboard," Chief Justice John Roberts wrote in his opinion.
Authorities accused Bond, a microbiologist, in 2007 of using chemicals -- including arsenic-based 10-chloro-10H-phenoxarsine that she allegedly stole from her company -- to try to poison a woman who allegedly was impregnated by Bond's husband.
Instead of being charged in state court, Bond was indicted in federal court on two counts of mail fraud and two counts of violating a federal law and international treaty on the possession and use of chemical weapons.
When a judge denied her motions to transfer the case to state court, Bond pleaded guilty and immediately appealed. She received a sentence of six years behind bars and nearly $12,000 in fines and restitution. She was released in August 2012.
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