CHICAGO (CBS) — A teen charged with killing his aunt’s boyfriend allegedly cut off the victim’s head and left it on his aunt’s bed “as a present” on Christmas Day, according to prosecutors.

Alexis Valdez, 18, has been charged with first-degree murder, for allegedly killing 41-year-old Silvestre Diaz-Hernandez inside a basement apartment in the 2500 block of North Kildare Avenue early Christmas morning.

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At a bond hearing Thursday afternoon, prosecutors unveiled a gruesome story in an attempt to keep Valdez detained. They say he had been living with his aunt and her boyfriend and was supposed to be helping pay the bills, but he had stopped working. After several arguments about the expenses, Valdez was asked to move out.

“The defendant’s behavior caused ongoing tension between the defendant and his aunt and the victim,” Assistant State’s Attorney Kingsley Sawyer told reporters.

Prosecutors said Valdez confessed to killing Diaz-Hernandez with a hammer, by hitting him several times in the head and smashing a hole in his skull.

Valdez allegedly used loud music and covered the apartment’s windows. He cut off the victim’s head, ears and nose and gouged out his eyes. He then placed the head on his aunt’s bed.

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“He wanted to ‘leave his aunt a present,’” Sawyer said.

He also allegedly cut off Diaz-Hernandez’s left arm and mutilated the body.

After the murder, Valdez called 911 to report a dead body in the apartment. When the operator asked if he had attempted CPR, he laughed and said the body had no head.

Police officers reportedly found Valdez covered in blood. The alleged killer made a chilling statement, according to the prosecutor.

“If his aunt had come home, and seen the victim’s body, then he would have killed her as well,” Sawyer said.

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Valdez was ordered held without bail Friday.