A Brazilian teen confessed to torturing and killing her five-year-old brother and eating his penis.

Karina Roque, 18, was discovered by her mother standing beside the mutilated remains of the former's brother, Maycon Roque, at their home in Sao Roque, Brazil, Thursday. Since the body was on the ground, surrounded by seven candles, investigators suspected the murder to be part of a black magic ritual.

The victim's mother, who was not named, said she had left her son in the suspect's care earlier in the day when she went shopping. When she got back a couple of hours later, the suspect refused to let her in the house. The mother said she had to get her brother-in-law, who lived in the neighborhood, to break down the door. The mother reportedly fainted after witnessing her daughter with her son's corpse.

As the teen tried to flee the scene of crime, she was restrained by her uncle and other relatives. "They tried to prevent her from running but she apparently became very aggressive and started throwing objects," Detective Anderson Góes said, the New York Post reported. "Her uncle was hit and injured by a stone and she bit the family dog, which attacked her while she was being restrained by relatives."

Investigators added that the victim's body was covered in fatal injuries – Maycon's wrists were slit, his head partially decapitated, eyeballs pierced and the feet were burned. There were also signs that parts of the body had been cannibalized. Preliminary examinations determined that the injuries were inflicted after the boy's death.

Karina admitted to luring her brother into her bedroom by pretending they were going to play a game. She then proceeded to suffocate him with a pillow, adding that she had "cut off her brother's genital organs and eaten it."

Detectives also recovered a burned cellphone, a memory card, a penknife and a small amount of marijuana in the house. The phone and the memory card were being analyzed by officials to retrieve additional information.

"We believe the cellphone belongs to the suspect and was deliberately damaged by her to possibly destroy any evidence of online contacts," Góes said. "We are investigating if the child was killed during some kind of devil worshipping ritual. We want to know if the accused had links on social networks to a group of Satanists or black magic practitioners and if she was encouraged or incited by someone to commit the crime. She will also undergo tests to see if she is under the influence of drugs."

Karina was charged with her brother's murder and with the attempted murder of her uncle. She was placed on suicide watch inside an isolation cell at Votorantim Women's Prison in São Paulo.

The teen's family, which cremated the victim's body Friday, said they never faced any problems with Karina before and that all her life she had "always taken care of her brother."

This article originally appeared in IBTimes US.