Gun deaths reached the highest number ever recorded in the United States in 2020, the first year of the pandemic, as gun-related homicides surged by 35 percent, the Centers for Disease Control and Prevention reported on Tuesday.

“This is a historic increase, with the rate having reached the highest level in over 25 years,” Dr. Debra E. Houry, acting principal deputy director of the C.D.C. and the director of the National Center for Injury Prevention and Control, said at a news briefing.

More than 45,000 Americans died in gun-related incidents as the pandemic spread in the United States, the highest number on record, federal data show. The gun homicide rate was the highest reported since 1994.

That represents the largest one-year increase in gun homicides in modern history, according to Ari Davis, a policy adviser at the Johns Hopkins Center for Gun Violence Solutions, which recently released its own analysis of C.D.C. data.

Cities from coast to coast have seen bloody episodes of gun violence since the pandemic began, but the new report is official confirmation of something that many Americans had already sensed: Amid the stress and upheaval, citizens turned to guns in numbers rarely seen.

The new numbers reveal not only startling increases in the rates of gun homicide, but also document “widened disparities” that existed even before the pandemic began, the C.D.C. said.

Homicides involving firearms were generally highest, and showed the largest increases, in poor communities, and exacted a disproportionate toll on younger Black men in particular. Deaths of Black women, though smaller in number, also increased significantly.

More than half of gun deaths were suicides, however, and that number did not substantially increase from 2019 to 2020. The overall rise in gun deaths therefore was 15 percent in 2020, the C.D.C. said.

The rise in gun violence has afflicted cities large and small, in both blue and red states, leaving law enforcement scrambling for answers. In many places, like Los Angeles and Denver, the increases have persisted in 2021, and trends this year so far show no sign of a reversal.

{snip}

Federal officials and outside experts were not certain what caused the surge in gun deaths.

“One possible explanation is stressors associated with the Covid pandemic that could have played a role, including changes and disruption to services and education, social isolation, housing instability and difficulty covering daily expenses,” said Thomas R. Simon, associate director for science at the C.D.C.’s division of violence prevention.

{snip}

{snip} Federal researchers also cited disruptions in routine health care; protests over police use of lethal force; a rise in domestic violence; inequitable access to health care; and longstanding systemic racism that has contributed to poor housing conditions, limited educational opportunities and high poverty rates.

{snip}

Black Americans remained disproportionately affected by gun violence in 2020. Firearm homicide rates increased by 39.5 percent among Black people from 2019 to 2020, to 11,904. The victims were overwhelmingly young men.

The Johns Hopkins analysis found that Black men ages 15 to 34 accounted for 38 percent of all gun homicide victims in 2020, though this group represented just 2 percent of the U.S. population.

Black men ages 15 to 34 were more than 20 times more likely to be killed with a gun than white men of the same age. The number of Black women killed by guns also increased by almost 50 percent in 2020 compared with 2019, Mr. Davis said.

Rising rates of gun-related homicides were seen in all racial and ethnic groups, except among Americans of Asian and Pacific Islander descent, who saw a small decrease.

{snip}