ORLANDO, Fla. – A 28-year-old woman stabbed her 11-year-old daughter to death Sunday because she thought the girl was having sex with men, according to an arrest affidavit.

Rosa Alcides Rivera faces first-degree murder charges in the death of her daughter, Aleyda.

Authorities said Rivera stabbed her daughter at least 15 times in a car and drove her to Winnie Palmer Hospital in Orlando. Hospital staff began to assist Rivera and realized her daughter was dead, the affidavit said.

Orange County Sheriff John Mina said Rivera stabbed the girl while inside the vehicle, then drove her around before going to the hospital, and by that point, the child was dead.

Hospital security surrounded Rivera and called an off-duty Orlando police officer who was working security at Orlando Regional Medical Center for assistance, and he placed Rivera in handcuffs, officials said.

Rivera had cuts near her wrist and was taken to a hospital, where she was cleared medically, officials said.

In an interview, Rivera first told detectives a man had stabbed her daughter before running away. She later said she had killed her daughter and her "baby is gone," according to the affidavit.

Officials said the incident began at a home on Citadel Drive, where Rivera had accused her mother's boyfriend of having sex with her daughter. Witnesses told officers that the girl had denied having sex with him, the affidavit said.

According to officials, Rivera said she killed her daughter to prevent her from having sexual relations with men. She said she believed her daughter was having sex with men because she "smiled different," according to the affidavit.

Mina said there appears to be no validity to Rivera's claim that her daughter was sexually active.

"We don't believe it's credible," Mina said.

Rivera also told detectives she attempted to make her daughter comfortable while she was stabbing her, according to authorities.

“We’re all parents, we’re all mothers and fathers, and these cases are horrific and tragic, especially any time a child is killed, and then to know that this child was killed by a mother. Basically, a mother is the first line of defense to this sometimes very cruel world," Mina said. "It’s very very hard on all of us in the community."

Officials said Rivera then harmed herself, resulting in the cuts to her arm, before she arrived at the hospital.

Although authorities did not say if Rivera had any prior contact with law enforcement, he said the incident comes as a reminder to report suspected domestic violence.

"I think the message is that domestic violence continues to happen not only in this community, obviously across the nation. When people see things, or notice things they need to call the authorities so that … we can stop these tragedies before they happen," Mina said.

Bianca Fernandez, a family friend, said Rivera moved back to the Orlando area from Texas in December and has been acting different ever since.

"She’s been starting problems with the whole family, like, everybody," Fernandez said. "She’s trying to look all crazy on TV. She knew exactly what she was doing."

Authorities said Aleyda Rivera attended West Ridge Middle School, where grief counselors will be on hand Monday to talk to her classmates.

"One of our students was tragically killed over the weekend. Our thoughts and prayers are with the family as they go through extremely difficult time," Principal Matt Turner said. "Your child may speak with you and share this sad news. Students will have varied reactions to the death of any peer. Any reaction is normal in the grief process and I encourage you to openly discuss with your child their feelings and reactions."

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