As pundits and average citizens reflect on the year past during this New Year’s Eve, Sen. Chris Murphy (D-Conn.) is marking grim milestones.

The pro-gun control lawmaker is tweeting details of each mass shooting this year in a painful reminder of what feels to be an especially horrific 12 months of violence. There have been almost as many mass shootings in 2015 — 353 — as there are days of the year, claiming the lives of more than 400 innocent Americans.

President Obama’s tireless advocacy for increased gun control and safety measures has met stalwart resistance in the Republican-controlled Congress, but he is reportedly planning to press ahead with new executive orders early next year in the hopes of cracking down on unlicensed sales and expanding background checks on gun purchases.

Murphy, a freshman senator who enjoys a 100% rating from the Brady Campaign to Prevent Violence, has been particularly outspoken on the issue of gun violence in the wake of the mass shooting at Sandy Hook Elementary School in Newtown, Connecticut, three years ago, which claimed the lives of 20 children and six adults.