Mass shootings in the United States drew an enormous amount of attention in 2015. In early December, the NewsHour plotted the locations of these shootings in a map, using data from the Mass Shooting Tracker. This post was widely shared across social media.

According to the Tracker’s data, which defines a mass shooting as an incident in which at least four people are killed or wounded, there were 372 mass shootings in the U.S. in 2015, killing 475 and wounding 1,870.

Elected officials and political candidates took to different platforms — from Twitter to TV interviews to the Senate floor — to express their thoughts and feelings following the incidents.

President Barack Obama, who has frequently had to take on the role of consoler in chief, sang “Amazing Grace” at the funeral service for Rev. Clementa Pinckney, one of nine people killed in a church shooting in Charleston, South Carolina, in June. Watch an excerpt of that in the video above.

President Obama is expected to take executive action next week to expand background checks on gun sales, according to an individual whose gun control advocacy group has been briefed by administration officials about the timing, the Associated Press reports.

Editor’s note: This post has been updated to reflect that Mass Shooting Tracker defines a mass shooting as an incident in which at least four people are killed or wounded. An earlier version did not reference those who have been wounded.