Head of Homeland Security reacts to chokehold case

(CNN) – Secretary of Homeland Security Jeh Johnson is urging people protesting the grand jury decision not to indict a New York police officer in the chokehold death of Eric Garner to stay peaceful.

"If you want change to come about as a result of an event like this, engage the political process in a positive way, in a positive, nonviolent way to bring about political change, which can also bring about change in how the criminal justice system in a particular jurisdiction is conducted," Johnson said in an interview with CNN's "The Lead with Jake Tapper."

President Barack Obama is pushing for body cameras for police officers, but Garner's mother said that would be a waste of money, saying video of the deadly incident between Garner and Pantaleo did not make a difference to the grand jury.

"It can be a good practice in certain circumstances," said Johnson. "I'd want to be mindful of whether it's practical in every single instance for a law enforcement officer."