House of Representatives Speaker Mike Johnson said his chamber would launch a bipartisan task force with subpoena power, as lawmakers received private phone briefings from security officials before expected public hearings next week.

“It’ll be comprised of Republicans and Democrats to get down to the bottom of this quickly, so the American people can get the answers that they deserve,” Johnson told Fox News.

Top Senate Republican Mitch McConnell said on social media, “New leadership at the Secret Service would be an important step in that direction.”

Secret Service director Kimberly Cheatle in a Tuesday interview with ABC News said she would not resign. Secret Service officials did not immediately respond to a request for comment on Wednesday.

The Saturday shooting wounded Trump in the ear, killed a rally attendee and injured two others. The 20-year-old gunman, who was shot and killed by security, fired from a rooftop about 140m from the stage where Trump spoke.

“Whoever made the decision not to cover that building. You know, that’s probably the biggest flaw in this thing,” Republican representative Mark Green, chairman of the House homeland security committee, said on Fox News.

Cheatle is due to testify next week in separate hearings before the House oversight and homeland security committees.