After 12-year-old Rebecca Sedwick killed herself last month, one of her tormenters continued to make comments about her online, even bragging about the bullying, a sheriff said on Tuesday.

The especially callous remark hastened the arrest of a 14-year-old girl and a 12-year-old girl who were primarily responsible for bullying Rebecca, Polk County Sheriff Grady Judd said. They were charged with stalking and released to their parents.

"'Yes, I bullied Rebecca and she killed herself but I don't give a ...' and you can add the last word yourself," the sheriff said, quoting a Facebook post the older girl made on Saturday.

Police in central Florida said Rebecca was tormented online and at school by as many as 15 girls before she took her own life on September 9. A dozen or so suicides in the past three years that have been attributed at least in part to cyberbullying.