Family members of a woman and man fatally shot by Chicago police say officers must stop killing residents.

Neighbours Quintonio LeGrier, 19, and Bettie Jones, 55, were shot and killed by police inside their apartment building on Saturday. 

Speaking at a news conference held Sunday outside the home where the victims were killed, LeGrier's mother, Janet Cooksey, said the Chicago Police Department has failed her and so many others.

USA CHICAGO POLICE SHOOT TWO PEOPLE

LaTonya Jones, right, is comforted by her father Garry Mullen as she holds a picture of her mother Bettie Jones during a vigil outside of the home where Jones was shot alongside neighbour Quintonio LeGrier. (Tannen Maury/EPA)

She said she used to watch the news and see other families who lost their loved ones to police shootings, and now it's happened to her.

"An innocent lady got shot as well because police just was [sic] trigger happy. I went to the hospital — my son has seven [bullet wounds] in him," she told a CNN reporter.

Jacqueline Walker, a friend of Bettie Jones who was also present at the news conference, asked why police "shoot first and ask questions later." She says they should use stun guns or other nonlethal methods instead.

Quintonio LeGrier

Quintonio LeGrier, 19, was shot and killed by Chicago police on Saturday. The Northern Illinois University electrical engineering student was "going somewhere" in life, according to his mother. (Handout photo)

Chicago Police Department said in a statement that Jones had been shot accidentally while officers responded to a domestic disturbance call.

The statement also said that when officers arrived at the home early Saturday morning, they "were confronted by a combative subject resulting in the discharging of the officer's weapon."

LeGrier's father, Antonio LeGrier, had reported that his son seemed "agitated" before the events that led to his son being fatally shot. The elder LeGrier said it was he who had called police on his son.

He said he also called to warn the downstairs neighbour, Bettie Jones, that his son was "a little irate" and that she shouldn't open her front door until police arrived. 

A pattern of deadly force?

The shooting is being investigated by the city's Independent Police Review Authority. The circumstances of the shootings aren't clear, including whether one or several officers opened fire and why. Both victims were black.

The Chicago Police Department is also the subject of a federal civil rights investigation.

Attorney General Loretta Lynch launched the investigation in early December. She said it will focus in particular on use of force and deadly force, including racial, ethnic and other disparities in use of force, and its systems of accountability.

That investigation was launched after last month's release of police dashboard camera video showing white officer Jason Van Dyke shooting black 17-year-old Laquan McDonald 16 times in 2014. The video's release has led to protests, the forced resignation of Chicago Police Superintendent Garry McCarthy and calls from residents for Chicago Mayor Rahm Emanuel to step down.

On Sunday, Emanuel called on the Chicago Police Department and the main police oversight agency to review crisis intervention training in the wake of a double fatal police shooting.
 
He said he wants the Independent Police Review Authority and the interim police superintendent to meet with each other as soon as possible to review the training around how officers respond to mental-health crisis calls.

It is not clear whether there are any video recordings of Saturday's shootings.

'We need relief in Chicago'

At the news conference on Sunday, Cooksey and Walker again called on Emanuel to step up and improve the police's dealings with the public, or step down from office.

Janet Cooksey

Janet Cooksey, the mother of Quintonio LeGrier, speaks to the media outside of her home, where her son and neighbour Bettie Jones were shot on Saturday morning. (CNN)

Cooksey said she wants a personal apology from Emanuel for what happened to her only child.

"Are we gonna get protected or is the police just gonna keep taking lives?" Cooksey said. "I mean, who's gonna answer these questions?"

After the news conference, about 100 people including neighbours and religious leaders held a vigil in neighbourhood streets, with many saying they did not trust the police to be truthful about what happened.
 
"This family is absolutely devastated," the Rev. Marshall E. Hatch of a neighbourhood church said in a statement early Sunday, adding that the shooting showed how "deeply dysfunctional the relationship is between this department and its citizens."

"We need relief in Chicago," Hatch said.

With files from the Associated Press, Reuters