A Brazilian man who admits he killed and dismembered a 17-year-old British girl while addled by drugs goes on trial Thursday, hoping for a reduced sentence based partly on his heavy drug use.

Mohamed D'Ali Carvalho Santos has confessed to killing Cara Marie Burke in the central Brazilian city of Goiania, and the prosecutor wants him sentenced to the maximum 30-year prison term.

But defense attorney Odair de Meneses said a psychiatric evaluation showed Santos was not "fully responsible for his acts because he was taking drugs nonstop during the three days prior to the killing." Meneses told The Associated Press he will argue for a 15-year sentence.

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He said Santos, who hid Burke's torso in a suitcase and scattered her body parts outdoors, was using as much as 50 grams of cocaine a day and even sniffing cooking gas to get high at the time of the killing.

"I think that if he responds well to psychiatric treatment in prison, he has a chance of rejoining society after 15 years," Meneses said.

State court records described Santos as "a mentally perturbed, anti-social individual prone to having hallucinations."

"He has demonstrated regret and a desire to pay for the crime he committed," said the report, posted on the court's Web site.

Santos recently underwent a battery of psychiatric tests at a detention center where he and his 20-year-old girlfriend conceived their son, who was born March 23. Brazilian prisoners have the right to conjugal visits.

Burke came to Goiania last year after she met Santos and his mother in London. Authorities say Santos and Burke were not boyfriend and girlfriend, but that Santos and his mother invited her for an extended visit.

Police said Santos, 21, killed Burke on July 25 after she threatened to tell his family that he was addicted to cocaine and was dealing the drug.

State police said that after killing Burke with a butcher knife, Santos went to a funk concert before returning to his apartment, stuffing her torso in a suitcase and hiding it near the banks of a river.

Police say Santos sent his brother a text message saying "the bitch is in the bag." The message, found in Santos' cell phone, was written in English, accompanied by a smiley face. The cell phone also contained photos of Burke's severed head and torso.

Santos scattered other body parts near another river. Authorities eventually recovered all her remains, and they were sent back to England two months after her killing.

Santos' lawyer said his client's confession and regret may help sway the jury and judge toward leniency.

Prosecutor Milton Marcolino said Santos deserves the maximum penalty for what he described as a "barbaric crime."

Santos "was perfectly aware of what he was doing and of the consequences of his acts, despite all the drugs he took," Marcolino said.