The attack comes amid a recent string of highly publicized incidents that have left staff on edge and are raising questions about security, especially away from Washington.

“Staffers are hurting right now,” said Michael Suchecki, a spokesperson for the Congressional Progressive Staff Association, who works in the office of Rep. Seth Moulton, D-Mass. “We pour our hearts into serving our communities and our country, but we’ve been shaken by the recent uptick in threats of violence, the online doxing of employees and a brutal attack on office staff.”

The attack at Connolly’s office came less than two months after a staffer for Sen. Rand Paul, R-Ky., was stabbed repeatedly while walking with a friend on H Street Northeast in Washington.  

Also in March, the Capitol Police seized an assault rifle from an individual “targeting and stalking a congressional staff member,” Capitol Police Chief J. Thomas Manger testified to the House Administration Committee on May 16.

And earlier this month, Ken Klippenstein, a reporter for The Intercept, attempted to “name and shame” staff working for Sen. Dianne Feinstein, D-Calif., by posting their names, pictures and some email addresses and salaries to Twitter, in a move that was broadly condemned by staff groups as a threat to their safety.