A Brazilian man has admitted to local police that he raped Japanese woman Hitomi Akamatsu before killing her.

Akamatsu's body was found in a ditch next to a waterfall last week. Police have identified the suspect as 18-year-old Rafael Lima da Costa.

Lima da Costa claimed during his first interrogation that he used Akamatsu's blouse to strangle her, and he did not rape her. 

But when Lima da Costa was interrogated again by the police after discovering the 43-year-old woman's clothing in an abandoned home, he confessed that she raped her.

The victim's underwear was also found in the woods. 

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Police have then indicted him for rape. Lima da Costa was also charged with homicide resulting from a robbery and for hiding a cadaver, according to a South China Morning Post report.

The Associated Press was not able to seek comment from the man. The suspect remains under preventative arrest.

Akamatsu moved to the city of Abadiania to seek treatment for skin cancer. This was after she survived a nuclear accident in Japan.

Akamatsu remained there after the arrest of the spiritual healer known as João de Deus or John of God, according to an AP News report.

João drew people from all over the world to his small city in Brazil with promises that he could treat everything from depression to cancer. Last year, the healer was found guilty of committing multiple rapes.

Akamatsu's body was found after her friend reported her missing. Authorities responded by sending out a search party with tracker dogs.

Security camera footage showed Lima da Costa following Akamatsu. He then later returned with her blouse slung over his shoulder.

A forensic report from Goiás state's crime lab revealed that cranial trauma or a head injury was actually the cause of death of the victim and not strangulation.

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Lima da Costa still believed that he had strangled her to death, according to detective Isabella Joy. He had also said that he had intended to rob somebody to pay off a drug debt.

Lima da Costa noted that the victim just happened to pass by, and she was not specifically the target, Joy added.

Nearly a week had passed between Akamatsu's death and the day her body was found. Joy said that the time elapsed, combined with the humid environment, triggered a fast decomposition and made it impossible to confirm whether she was raped.

The detective also said that Lima da Costa does not have a lawyer and will most likely be appointed a public defender.

Between 1980 and 2018, the Brazilian homicide rate rose the highest worldwide. Rates of self-reported offending are also relatively high among high school children in Brazil.

According to a study, individual as well as family risk factors are also similar to those in high-income countries.

Meanwhile, Brazil has the lowest rates of drug use as compared to other countries such as the United States. But the rampant drug use among youth in Brazil has increased significantly over the years.