CBC News has learned Edmonton police do not plan to lay any criminal charges in last month's death of a young Somali-Canadian man.

Yusuf Abdirahim, 20, was found unconscious in northeast Edmonton near 149th Avenue and 70th Street around 3 a.m. May 19.

Abdirahim was allegedly beaten by another young man. He died in hospital May 21.

Abdirahim's death was ruled a homicide by the medical examiner but his family has been told that no charges will be laid in the case.

"They said the police told her they have the guy who killed her son — but it was a matter of self-defence. Therefore [they're] not going to arrest him," said Abdirahm's mother Farida Adan through an interpreter.

The lead homicide detective will only say the Crown prosecutor is now being consulted on the case. But a police source confirms what the victim's mother has been told — no charges will be laid..

According to some witnesses, Abdirahim was the aggressor in the altercation. He was punched in the face, fell backwards and later died from head injuries.

CBC News has been told the young man who delivered the punch has been co-operative with police.  He's been allowed to return home to Saskatchewan.

The situation leaves an already heartbroken mother even more devastated and angry.

"I want justice for my son and I wanted the person who killed my son to be brought to justice," Adan said.

With files from the CBC's Janice Johnston and Scott Fralick