This Dec. 26, 2013 photo provided by the Chicago Police Department shows 18-year-old Alexis Valdez, who was charged Thursday, Dec. 26, 2013, with first-degree murder in the death of 41-year-old Sylvester Diaz-Hernandez whose body was found decapitated inside an apartment on Christmas on Chicago's Northwest Side. (AP Photo/Chicago Police Department)

An 18-year-old Chicago man has been ordered held without bail after he allegedly decapitated and dismembered his aunt's boyfriend in the early morning hours of Christmas Day.

Officials said Friday that Alexis Valdez called 911 after he killed 41-year-old Silvestre Diaz-Hernandez inside the basement apartment where the two lived with Valdez's aunt in the city's Belmont Gardens neighborhood, the Chicago Tribune reports.

Prosecutors say Valdez had been living in the apartment in the 2500 block of North Kildare Avenue for about six months on the condition that he would go to school, work and contribute to household costs. When he failed to do that, his aunt told him he needed to move out, angering the teen, according to the Chicago Sun-Times.

While Valdez's aunt was away at a party, Valdez was home drinking and, after accompanying Diaz-Hernandez to a drug store to buy more beer and returning to the apartment, he allegedly struck the man multiple times in the head with a hammer he had hidden.

UPDATE Dec. 29 -- A GoFundMe page has been set up for Diaz-Hernandez's brother in order to raise funds for the man's funeral. According to the fundraising page, the 41-year-old did not have life insurance.

The Sun-Times further reports that, after Diaz-Hernandez was dead, Valdez proceeded to use a butcher knife to decapitate the man and cut off his ears, nose and mouth, as well as his arms. Prosecutors say he pulled Diaz's eyes out of his head using his bare hands.

The teen allegedly left the head and other parts in her aunt's bed because "he wanted to leave his aunt a present," prosecutors said on Friday, according to DNAinfo Chicago.

When police arrived on the scene, the blood-covered teen admitted to the grisly slaying, ABC Chicago reports.