Officer-involved shootings are not tracked in the Uniform Crime Reporting statistics the FBI gathers from local police departments every year.
But that could change as the agency considers adding use of force by and against police officers to the list of violent crimes and property crimes counted nationwide, said Steven Casstevens, president of the Illinois Association of Chiefs of Police and police chief in Buffalo Grove.
Officer-involved shootings in suburbsThere have been at least 22 fatal officer-involved shootings in the Daily Herald's circulation area in the past 17 years. Here's a quick look back:
Jan. 2, 2017: Villa Park-area resident Trevon Johnson, 17, is shot and killed by a DuPage sheriff's deputy responding to a domestic violence call.
October 2016: An Aurora officer exchanges gunfire with an 18-year-old who led officers on a chase after police smelled cannabis when they pulled him over for a traffic stop. The man shoots himself in the head.
September 2016: A Round Lake officer fatally shoots 22-year-old Michael Robert Musson Jr. of Grayslake, who confronted officers with a shard of glass, after callers reported a man pounding on the doors of townhouses.
April 2016: Gerald R. Boyes is shot outside a bar near Antioch after waving a handgun at Lake County and McHenry County sheriff's deputies who were trying to arrest him on suspicion he was responsible for two murders in Kentucky.
October 2015: Three Lisle officers responding to a call of a home invasion shoot and kill 35-year-old Anthony Aguilar of Lisle, who had tried to kick down doors, broken into the detached garage and broken several windows on a vehicle.
April 2015: Zion police shoot and kill 17-year-old Justus Howell of Waukegan, who had gotten into a fight while trying to steal a handgun, sparking protests and rallies calling for police diversity and institutional reforms.
January 2015: An off-duty Rosemont officer shoots and kills his brother-in-law, 31-year-old Joseph Caffarello, after a domestic disturbance.
November 2014: Two Highland Park police officers shoot and kill Christopher Anderson, 27, of Waukegan, a patient in an emergency room when he pulled a gun on hospital workers and officers.
March 2014: Two Sleepy Hollow police officers shoot and kill a man brandishing a knife and attempting to cut two officers after a domestic disturbance that left two others injured.
December 2013: Arlington Heights police shoot and kill Eric M. Anderson, 41, of Niles after he took his ex-girlfriend hostage in her mother's townhouse. Anderson also shot an Arlington Heights police officer in the face.
July 2013: A Kane County sheriff's sergeant shoots Batavia Township resident Luke Bulzak, 53, after he threatened to kill himself, would not drop his weapon and pointed it at deputies.
May 2012: Des Plaines police shoot Carlos Salgado, 44, a known gang member of Elk Grove Township, during a confrontation after a traffic stop.
March 2011: Two Naperville officers shoot and kill a suicidal Aurora man, 47-year-old William Ladew, after he advanced on police with a knife.
January 2011: An off-duty Aurora officer shoots a 15-year-old Aurora boy who was shooting at a crowd of teens and refused to drop his gun.
August 2010: Daniel Moreno, 28, dies from injuries sustained in a shootout with police at his home in Arlington Heights after a standoff following a domestic incident.
December 2009: Des Plaines police shoot and kill Krzysztof Kaczor, 24, after he threatened an officer with a long-handled ax.
September 2006: David S. Maxson, 43, of Wonder Lake dies after a standoff at his home ended with a McHenry County sheriff's deputy shooting him three times with a shotgun loaded with beanbags. One of the bags pierced Maxson's skull, causing a fatal brain injury.
May 2006: A Marengo police officer shoots and kills Jose Manuel Aldava-Grijaldo, 21, who was the only suspect in the slaying of an elderly Marengo woman during an apparent robbery in her home earlier that day.
November 2004: Crystal Lake resident Kevin Cronyn, 31, is shot dead by police after a high-speed chase when he began ramming his pickup into occupied squads.
December 2001: Joseph Frustaci of Bloomingdale is killed in an exchange of gunfire with Glendale Heights police after shooting his live-in girlfriend, Karen Robin.
March 2001: Robert J. Hejsak, 33, of Spring Grove, Wisconsin, is shot by police after a three-hour standoff in Ringwood and an exchange of 37 shots between Hejsak and eight police officers, mostly from the McHenry County sheriff's department.
January 1999: Batavia resident Raul Montalvo is killed in an exchange of gunfire with two officers after he pulled a rifle on police when they arrived at his home to serve a warrant.
The chiefs association Casstevens leads doesn't maintain a log of shootings by officers, either. But even during a time when officer-involved shootings gain national recognition on social media, suburban police officials say such episodes are relatively uncommon.
"It's not as prevalent as it may seem," Oak Brook Chief James Kruger said.
For example, in 2016, there were five officer-involved shootings in the Northwest and West suburbs, and three of them were fatal.
Officers are trained in de-escalation techniques to help avoid use of force. But it's tough for officers to rely solely on verbal tactics when a suspect is already showing physical violence, Casstevens said.
"The greatest percentage of the time, the police officer is responding to aggression from the subject," Casstevens said.
If the officer's life or the life of another person is in jeopardy, officers must make split-second decisions.
"These things happen so rapidly," Kruger said. "We're asking our officers to do a lot depending on the circumstances."
When an officer is involved in a shooting, it's standard procedure for an internal investigation to be conducted and an outside agency to run an independent probe to determine whether the use of force was justified.