Despite ongoing national scrutiny of police tactics, the number of fatal shootings by officers in 2016 remained virtually unchanged from last year when nearly 1,000 people were killed by police.

Through Thursday, law enforcement officers fatally shot 957 people in 2016 — close to three each day — down slightly from 2015 when 991 people were shot to death by officers, according to an ongoing project by The Washington Post to track the number of fatal shootings by police.

The Post, for two years in a row, has documented more than twice the number of fatal shootings recorded by the FBI annually on average.

As was the case in 2015, a disproportionate number of those killed this year were black, and about a quarter involved someone who had a mental illness. In a notable shift from 2015, more of the fatal shootings this year were captured on video.

Dozens of departments have vowed reforms since the killing of Michael Brown in Ferguson, Mo., in August 2014 launched a national debate over police use of force. Many agencies have equipped officers withbody-worn cameras, with prominent police chiefs vowing to further curb fatal encounters. But experts say an impact on fatal shootings may take years.

“Making these kinds of changes is very difficult on such a widespread scale,” said Chuck Wexler, executive director of the Police Executive Research Forum, a Washington-based think tank pushing for national police reform. “But quite frankly, we’re still on the front-end of the training that we’re pushing out. It may be at least six months to a year until we start to really see those numbers come down.”

The Post began tracking fatal shootings by officers after the deaths of Brown and others during police encounters. The federal government does not comprehensively record how many people are killed by police annually and depends on voluntary reporting from police departments. The Post’s database — which will continue in 2017 — largely relies on local news coverage, public records and social-media reports.

In the second year of tracking, The Post found:

• White males continued to be those most often killed, accounting for 46 percent of this year’s deaths — about the same as in 2015. But when adjusted by population, black males were three times as likely to die as their white counterparts.

• The percentage of fatal shootings of unarmed people declined in 2016, from 9 percent in 2015 to 5 percent. Black males, however, continued to represent a disproportionate share of those: 34 percent of the unarmed people killed this year were black males, although they are 6 percent of the population.

• Of all those who were shot and killed, 84 percent were armed, most with a gun or knife. Four percent wielded imitation firearms. In 7 percent of the fatalities, it was unclear whether the person was armed.

• As was the case last year, about 1 in 4 people fatally shot by police in 2016 were grappling with a mental health issue.