The Secret Service has put six individuals on unpaid suspension following an attempted assassination of President Donald Trump last July, an agency official informed NBC News.

The suspensions occurred after an investigation into the incident in Butler, Pennsylvania, where a bullet from a gun grazed Trump’s ear. Both supervisors and regular agents faced suspensions, which varied from 10 to 42 days without pay. The exact timeline of when these suspensions were enacted is not specified.

NBC News has highlighted that several Secret Service officials were placed on leave due to their conduct surrounding the assassination attempt. Those on leave included the special agent heading the Pittsburgh field office, which managed security arrangements in collaboration with local law enforcement before the rally.

Almost immediately after the assassination attempt, lawmakers of both parties questioned the security failures that gave a 20-year-old gunman the opportunity to target and shoot Trump and kill firefighter Corey Comperatore, in what federal officials called an act of potential domestic terrorism.

Less than two weeks after the incident, Kimberly Cheatle stepped down as director of the Secret Service amid bipartisan calls for her resignation. At the time, she said she took “full responsibility for the security lapse.”

In an interview with ABC News before she resigned, Cheatle said there was a “short period” of time between when the gunman was initially flagged as suspicious and when he began shooting. A Senate briefing later revealed that Secret Service agents first spotted the gunman on a rooftop 10 minutes before Trump took the stage and 20 minutes before he opened fire. Secret Service personnel also faced criticism for how long it took to remove Trump from the stage after he was shot.

In December, a House task force investigating the incident made nearly a dozen recommendations for the Secret Service, including recording all radio transmissions and logs and creating new roles “for high-pressure moments.” In a 180-page report, the task force determined that the Butler shooting was “preventable” but concluded there was not a “singular moment or decision” by the Secret Service that enabled the gunman to “nearly assassinate” Trump.

The House investigation, however, praised the response of the Secret Service to the second assassination attempt on Trump in September in West Palm Beach, Florida, crediting it for demonstrating “how properly executed protective measures can foil an attempted assassination.”