UPDATED 2:35 p.m. 12/30/15

CHICAGO (CBS) — Mayor Rahm Emanuel and interim Chicago Police Supt. John Escalante announced changes in the Police Department’s policy on the use of force, and a major expansion of the use of Tasers during a press conference Wednesday afternoon.

Under the plan, the department will add 700 Tasers, doubling the current amount, and officers will receive training on using them by June 1, 2016.

Currently, training in the use of Tasers is voluntary, and only about 20 percent of the force has been trained on how to use stun guns.

“Ultimately, what we are doing is injecting some humanity into the work of our police department and the police officers,” Emanuel said. “That is what these new policies will help us do.”

Supt. Escalante said that they studied 15 other police departments around the country in coming up with the new policy.

Besides adding new equipment, officers will be trained in a five-step de-escalation approach, to learn tactics on defusing hostile situations to figure out the best course of action, without the use of deadly force when possible. The new training begins next week.

“The policy changes center around de-escalation tactics to reduce the intensity of a conflict or a potentially violent situation at the earliest possible moment, emphasizing that the foremost goal is to protect the safety of all involved,” the mayor’s office said in a brief statement Tuesday night.

The changes are just the latest in a series of steps the mayor has taken to address concerns about police tactics in the wake of last month’s release of dashboard camera video showing a white police officer fatally shooting black teen Laquan McDonald in October 2014. Officer Jason Van Dyke has been charged with murder and official misconduct in McDonald’s death.

Van Dyke shot the 17-year-old 16 times after responding to calls about a person slashing tires on the Southwest Side. McDonald was carrying a small knife, and ignoring police orders to drop the weapon. Officers at the scene requested backup from an officer with a Taser, but before one could arrive, Van Dyke shot and killed McDonald.

Wednesday’s announcement about expanding use of Tasers comes on the heels of another fatal police-involved shooting, which claimed the lives of 19-year-old Quintonio LeGrier and 55-year-old Bettie Jones. Police have acknowledged Jones was accidentally killed when an officer opened fire on LeGrier while responding to a domestic disturbance call, after LeGrier became combative.

It was the department’s first use of deadly force since the release of the McDonald video, although it is unclear if any officer at the scene of this weekend’s police shooting was equipped with a Taser.

The mayor cut short his family vacation in Cuba after the shooting. Emanuel was met by protesters when he returned to his Ravenswood home on Tuesday. Activists spent more than six hours outside his house, demanding the mayor resign.

Several aldermen already have called for all officers to be trained and equipped with stun guns.

“We have to start looking at other ways, other avenues to deescalate the situations,” Ald. Ray Lopez (15th) said. “We’ve seen that in the Laquan McDonald where calls for a Taser were made to the scene and a Taser was not readily available.”

The Police Department already is the focus of a Justice Department civil rights investigation, and federal authorities have said the shooting of LeGrier and Jones would be part of its probe of the Chicago Police Department’s policies and practices regarding the use of deadly force.

Chicago Fraternal Order of Police president Dean Angelo has said he expects the Justice Department probe to result in more training and more equipment for officers.

“I think technology is a big part of what they’re going to look at,” he said.

Emanuel also previously announced the formation of a blue ribbon task force to review the department’s training, oversight, and disciplinary proceedings.