Nearly 1,500 confirmed police-involved deaths have occurred in the U.S. since January 2014, according to data collected by an activist group.
Scant official data about police killings in which the use of force is not deemed legally justified has prompted a number of activist groups to begin compiling their own statistics by using crime and media reports.
One such group, Killed By Police, logged nearly 1,500 police-involved deaths between Jan. 1, 2014, and April 30, 2015, according to a compilation made by the news website Vocativ.
The website describes itself as a media and technology venture that "explores the deep Web in order to discover stories and generate original content."
The actual figure could be much higher than 1,500, as it only includes confirmed incidents.
National headlines have been often dominated by a string of recent police-involved killings of black suspects over the past year, including Michael Brown in Missouri, Eric Garner in New York and Freddie Gray in Baltimore.
The incidents have stirred racial tensions, setting off nationwide protests over perceived injustices within the U.S. justice system.
They have also raised questions about what it takes for police officers to face criminal charges for excessive use of force.
According to an analysis by The Washington Post and researchers at Bowling Green State University, only 54 officers were charged during the past decade for fatally shooting someone while on duty.
"These represent a small fraction of the thousands of fatal police shootings that have occurred across the country in that time," the Post said in an accompanying report published April 11.