WINTER HAVEN, Fla. -

Two girls were arrested in a Central Florida cyberbullying case after one of them admitted online over the weekend that she harassed a 12-year-old girl who killed herself last month, a sheriff said Tuesday.

Polk County Sheriff Grady Judd said they arrested 14-year-old Guadalupe Shaw because they were worried she would continue bullying other girls. Guadalupe is accused of bullying 12-year-old Rebecca Sedwick, who climbed at tower at an abandoned concrete plant Sept. 9 and hurled herself to her death.

Judd said the teen was arrested after she posted online Saturday that she bullied Rebecca and she didn't care.

According to Judd, the 14-year-old, using the name Guadalupe Borgen, posted on Facebook, "Yes ik I bullied REBECCA nd she killed her self but IDGAF."  Judd said Borgen is the last name of Guadalupe's boyfriend.

"We decided that we can't leave her out there. Who else is she going to torment?  Who else is she going to harass?" Judd said.

A man who answered the phone at Guadalupe's Lakeland home identified himself as her father and told The Associated Press that his daughter was "a good girl" and he was "100 percent sure that whatever they're saying about my daughter is not true."

Police also arrested 12-year-old Katelyn Roman, who's also accused of bullying Rebecca, her former best friend, according to Judd. Both have been charged with felony aggravated stalking.

Judd said the bullying began after the Guadalupe started dating a boy that Rebecca had been seeing.

She "didn't like that and began to harass and ultimately torment Rebecca," Judd said.

Judd said Guadalupe turned Katelyn against Rebecca, and other girls also stopped being friends with her in fear of being bullied.

Authorities have said Rebecca was "terrorized" by as many as 15 girls who ganged up on her and picked on her for months through online message boards and texts.

According to investigators, witnesses said that Guadalupe once told Rebecca "to drink bleach and die" and said she should kill herself.

Judd said neither girl's parents wanted to bring their daughters to the sheriff's office, so detectives went to their homes and arrested them.

Judd said Guadalupe was "very cold (and) had no emotion at all upon her arrest."

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