MILWAUKEE (CBS 58) - A 20-year-old suspect is accused of beating a man, posting videos of the assault on Snapchat and leaving him in an alley to die.

The body of Delvin Mendoza-Chaparro was discovered on December 19 behind the garage of a home on South 6th Street in the City of Milwaukee.

A criminal complaint details the investigation into the 20-year-old's death.

A Milwaukee Police Detective investigating the report of a deceased person said Mendoza-Chaparro was wearing a Marquette University sweatshirt and Levi jeans. He was not wearing any socks or shoes. Wind chills on the night of Dec. 18 and 19 reached negative temperatures.

An autopsy found Mendoza died from "multiple blunt force injuries of the head." This is consistent with the investigating detective's report. He observed numerous abrasions on Mendoza-Chaparro and said his face and neck appeared to be severely battered.

Two people are facing first degree reckless homicide charges. Devin Katzfey and Sarah Zakzesky, both 20. 

Zakesky spoke with police about the events leading up to Mendoza-Chaparro's death. She told investigators the night before he died, Devin Katzfey, his brother and her roommate were smoking marijuana at an apartment. Mendoza-Chaparro told her he was going to come over. Zakzesky said she fell asleep before he did.

Zakesky told police she woke up in the middle of the night and found Mendoza-Chaparro sleeping on the floor in the living room. She went back to sleep and was woken up by Katzfey. She told police he was upset and accused Mendoza-Chaparro of stealing a bong, a pipe and other items.

Katzfey claimed he saw the stolen items in Mendoza-Chaparro's coat.

Zakzesky told investigators Katzfey dragged Mendoza-Chaparro into the kitchen and started beating him. According to the criminal complaint, Katzfey was throwing punches and kicking Mendoza-Chaparro repeatedly. Zakzesky estimated he hit him 25 times. She told police Katzfey's brother joined in on the beat down, hitting Mendoza-Chaparro about five times. At this point, Zakzesky said, Mendoza-Chaparro was unconscious. She also admitted to hitting and kicking him.

The criminal complaint reads: "[Zakzesky] stated that the victim had no chance and he didn’t have a chance to raise his fists and fight man to man."

Police are investigating three Snapchat videos recorded during the beating. Zakzesky said Katzfey recorded Mendoza-Chaparro from the victim's own Snapchat account.

Police recovered all three videos and describe them in the criminal complaint.

In the first video, Mendoza-Chaparro's badly battered face is shown. He is injured, but appears to be alive. A voice can be heard taunting the victim: "You know who this is, this Superman."

In the second video, Mendoza-Chaparro is lying on his side in what appears to be an apartment. The victim is clearly hurt. The voice on the video says, “That’s what happen when you fight.”

According to the criminal complaint, the person recording the video turns the camera on himself. Katzfey’s Facebook account is listed under the name SupermanX74.

In the third video, the victim attempts to get up and Katzfey kicks him down to the ground.

This is what happens next according to Zakesky. She told investigators she drove Mendoza-Chaparro and Katzfey to the area of South 6th Street. She claims she told Katzfey they needed to get Mendoza-Chaparro help, but he said no. She told police she stopped the car and Katzfey was holding Mendoza-Chaparro, when he fell into the snowbank. 

According to the criminal complaint, police asked Zakesky what she thought would happen when they left him there, and she said she didn't know.

Zakesky said they left Mendoza-Chaparro in the snow.

Zakesky and Katzfey are charged with first degree reckless homicide. There is an arrest warrant out for Katzfey.