A Winnipeg mother can't believe her son is gone. Sharon Shymko lost her 17-year-old son Michael Langan Tuesday afternoon. He died after police shot him with a Taser.

Police say Langan had a knife and refused to drop it.

"They took away my son and they should not have," Shymko told CTV News reporter Stacey Ashley. "This should not have happened. My son's not here, and there's nothing else I can say."

Langan was tasered in a back lane near William Avenue, close to Arlington Street. He was pronounced dead later in hospital.

Her son liked to box and dreamed of becoming a cabinet maker.

Shymko says her son wasn't an angel, but didn't deserve to die.

Michael Langan is the first person to die after being tasered by Winnipeg police.

Officers say two men spotted a 17-year-old stealing something from a vehicle Tuesday afternoon.

Those men followed the teen and flagged police down for help.

"Refused to comply"

When officers encountered Langan in a back alley, they say he was armed with a knife.

"They repeatedly asked him to disarm himself and to drop the knife," const. Jacqueline Chaput said. "The male refused to comply and at that point the electronic control device was deployed.

"[His action] posed a threat to the officers that poses a threat to the public and officers made the decision to deploy the electronic control device."

The family is already calling for a moratorium on Tasers.

"They should have just taken a gun and shot my son right there instead of using the Taser," Shymko said. "Basically it did the same thing."

She says Langan was healthy and has no idea how her son could have died after being shot.  Police won't say how many times the teen was tasered.

Sources tell CTV News an autopsy was performed Wednesday, but the results could take some time.

Lengthy investigations just beginning

The autopsy is only the beginning of a lengthy investigation. Because this is an officer involved fatality, the Winnipeg Police Homicide Unit is investigating. After that it's protocol to go to an outside agency for review.

That review goes to the Attorney General, and then there's a mandatory inquest into the teen's death.

The officers involved have been put on administrative leave, which is normal police policy.