CHICAGO — Mayor Rahm Emanuel said Wednesday that Chicago police must be better trained to distinguish between when they can use a gun and when they should use a gun, after a series of shootings by officers sparked protests and complaints that police are too quick to fire their weapons.

Emanuel announced changes in police training and department policies on use of force during a news conference. He also said the Police Department will double the number of Tasers available to officers – from 700 to 1,400 – as he works to restore public trust in the police force and his administration.

“Our police officers have a very difficult and dangerous job. They put their lives on the line so the rest of us can be safe. And like all of us, they are human and they make mistakes,” the mayor said. “Our job is to reduce the chances of mistakes.

“That requires us to give them the right guidance, the right training, and the right culture, to prevent abuses,” he said. “Willful misconduct and abuse cannot and will not be tolerated.”

Emanuel pledged training to make police encounters with citizens “less confrontational and more conversational.” He said “force should be the last option and not the first choice.”

Every police patrol car will be equipped with a Taser by June 1, 2016, he said.

Interim Police Superintendent John Escalante said the city looked at 15 police departments, including New York, Seattle, Cincinnati and Cleveland as it developed its policy changes.

Emanuel and Chicago police have been under heavy scrutiny since the city, under court order, released a squad car video last month showing white officer Jason Van Dyke shooting black 17-year-old Laquan McDonald 16 times in 2014.