A Georgia man who had blamed the COVID-19 vaccine for making him depressed and suicidal has been identified as the shooter who opened fire late Friday on the U.S. Centers for Disease Control and Prevention headquarters,

The suspect in the shooting targeting the Centers for Disease Control and Prevention had letters that showed his “discontent” with COVID-19 vaccines.

Public health workers and gun safety advocates gathered at a rally Tuesday night to commemorate last week’s deadly shooting near Emory University and the Centers for Disease Control and Prevention, and demand policy changes to prevent future instances of gun violence.