A Mississippi police officer shoots an 11-year-old boy who dialed 911 to report a domestic disturbance.

Attorneys file a lawsuit on behalf of a Georgia woman who died after calling 911 for mental health help and falling out of a moving police car while handcuffed.

A New Jersey police officer is charged with manslaughter in the fatal shooting of a man who called 911 to report an armed trespasser. The man was still on the phone with a dispatcher when he was shot in his front yard.

The slew of cases this week renews questions about who should respond to emergency calls — and what needs to change to prevent pleas for help from turning deadly.

“When residents call 911 for service, they are concerned, they need assistance, they seek protection — and they trust the officers responding to their calls will respond accordingly and help them,” New Jersey Attorney General Matthew Platkin said in a statement. “Tragically, that did not happen here.”

While each of the cases in Mississippi, Georgia and New Jersey has unique circumstances, the outcomes in each come down to issues of police hiring, training, policy and accountability, said Chuck Wexler, executive director of the Police Executive Research Forum.

“When you look at each case, each one inevitably makes you step back and ask, how could this happen?” Wexler said.

How often do police injure, kill people who call 911?

Policing fatality data is notoriously poor, and the data that is collected is not granular enough to capture how often police injure or kill someone who calls 911, said Jorge Camacho, policy director of the Justice Collaboratory, a research center at Yale Law School.