Washington, Apr 23 (IANS): US civil right activist Al Sharpton has demanded a federal investigation into the fatal shooting of Patrick Lyoya, a 26-year-old black man in the state of Michigan.

Lyoya was killed by a police officer on April 4 during a traffic stop, reports Xinhua news agency.

According to videos released by Grand Rapids police, the officer asked for Lyoya's driver's license, and Lyoya eventually fled the car and a chase on foot ensued.

The two men ended up struggling over the officer's stun gun before the officer shot Lyoya in the back of the head.

During the Lyoya's funeral on Friday, Sharpton addressed the officer and questioned his decisions: "You turned a traffic stop into what appears on tape to be an execution."

He pointed out that Lyoya was killed on the 54th anniversary of Martin Luther King Jr.'s 1968 assassination.

The activist also criticized Grand Rapids police's decision to withhold the name of the officer who fatally shot Lyoya unless he is charged with a crime, local media reported.

An autopsy found that the cause of Lyoya's death was a bullet shot to the back of the head.

The Michigan State Police is investigating the shooting death.

Hundreds of mourners attended Lyoya's funeral, according to media reports.