Accountability for the members of the Secret Service who were at fault for the July 13 assassination attempt against President-elect Donald Trump is “occurring,” Acting Director of the Secret Service Ronald Rowe will tell a House panel investigating the incident.

“All disciplinary measures are imposed to promote the efficiency of the Secret Service and to encourage behaviors and principles that ensure the success of the agency’s mission,” according to a copy of Rowe’s written testimony, which was obtained by ABC News.

“Employees receiving proposals of discipline will be provided due process under agency policy as well as any applicable laws and regulations. But, let me be clear, there will be accountability, and that accountability is occurring. Consistent with applicable laws and regulations, I cannot comment further on specific disciplinary actions underway or being considered.”

Suspected gunman Thomas Matthew Crooks opened fire during the rally in Butler, Pennsylvania, shooting Trump in the ear, killing one spectator and injuring two others.

A Secret Service Mission Assurance report was released earlier in the year, along with a Department of Homeland Security independent review and a Senate report.

Rowe will testify that since becoming director he has focused on preventing another July 13 shooting from happening again.

In his memo, he said the Secret Service increased its staffing levels on the president-elect’s detail, expanding the use of drones at venues, expanding counter-drone technology at venues, addressing the faulty radio issue by working with the Defense Department, using other federal law enforcement agencies to help with protective visits and expanding the ballistic countermeasures at Secret Service protected events.

At the president-elect’s residences, the Secret Service has worked with state and local partners to bolster security and use cutting-edge technology to do so.

“My goal is to improve our mission effectiveness and rebuild public trust,” according to Rowe’s written testimony. “One of the key systemic changes was the directive to mandate a unified command in a singular location for all protective sites, something that was not done on July 13th in Butler. This co-location enhances our communications and intelligence-sharing mechanisms with state, local and federal partners to better anticipate threats and respond to them more swiftly.”

In his written testimony, Rowe said that he has also prioritized the mental health of agents, adding a chief wellness officer just this week.

“While I cannot undo the harm that has been done, I am committed to doing everything in my power to ensure that the Secret Service never has a failure like this again.”