The recent stay of an assault charge against a Mountie who put his knee on a man's neck for more than three minutes during an arrest as the man cried "I can't breathe" exemplifies unfair double standards that seem to be at play when police are accused of wrongdoing, says a law professor who studies officers charged with crimes.

"It signals to the public that police officers can act with a certain level of impunity," said Danardo Jones, a criminal defence lawyer and assistant professor of law at the University of Windsor.

"It erodes trust in our criminal justice system. It erodes trust in the police."

An assault charge against Manitoba RCMP Const. Eric Gerein was stayed on Nov. 3 following an incident at Winnipeg's airport caught on cellphone video.

That Aug. 1, 2019, video showed Gerein kneeling on Nathan Lasuik's neck and placing the man's face against the ground during an arrest, as Lasuik pleaded with the officer to let him breathe.