WASHINGTON (NewsNation) — Hours after one of the most gruesome mass school shootings in history, the man President Joe Biden tapped to run the agency that regulates gun sales and shooting investigations is set to testify before senators.

Former federal prosecutor Steve Dettelbach is set to answer questions Wednesday about how he would run the Bureau of Alcohol, Tobacco, Firearms and Explosives. Dettelbach was nominated by Biden in April with the timing of the hearing being pure coincidence.

An 18-year-old gunman killed 19 children and two adults as he went from classroom to classroom at a Texas elementary school, officials confirmed Monday. The attacker was killed by a Border Patrol agent who rushed into the school without waiting for backup, according to a law enforcement official.

Dettelbach is expected to be questioned about the Texas mass shooting at the hearing.

The position as head of the ATF used to not be as controversial as it is now. Biden had to withdraw the nomination of his first ATF nominee, gun control advocate David Chipman, after it stalled for months because of opposition from Republicans and some Democrats in the Senate. The nominee will need a simple majority to be confirmed.

The last time the Senate actually confirmed a director for the agency was in 2013. Since then it has been a series of “acting directors,” mainly because of the gun lobby. Groups like the NRA spend millions of dollars lobbying Congress against any nominee to run the ATF that the organization believes will be too strict on gun control measures. The NRA claimed it spent more than $2 million to oppose Chipman. Even former President Donald Trump’s nominee for the ATF was pulled because of the same type of lobbying, with the agency ultimately running under an acting director for Trump’s entire presidency.

However, more than 140 former Justice Department officials, including two past attorneys general, threw their support behind Dettelbach to run the ATF. The ex-officials, who worked for both Democratic and Republican presidents, urged congressional leaders to quickly confirm Dettelbach to the post. Their endorsement comes on the heels of support from several law enforcement organizations, including the Major County Sheriffs of America.

Dettelbach is a former federal prosecutor who served as U.S. attorney in Ohio from 2009 to 2016 and has run in the past for attorney general of Ohio. He worked in several other positions in the Justice Department and was involved in the prosecution of a man who firebombed an Ohio courthouse. He also served as the chairman of the civil rights subcommittee as part of the attorney general’s advisory committee under former attorneys general Eric Holder and Loretta Lynch.

“With the surge in gun crime across our country in recent years, it is all the more important to have confirmed leadership at the helm of the ATF who will help keep our communities safe by taking gun traffickers and other violent criminals off our streets,” says a letter by the more than 140 former Justice Department officials, dated Wednesday.

Biden has sought to increase gun control in the country, including restricting ghost guns.

There have been more than 900 incidents of gunfire reported on school grounds since the tragedy at Sandy Hook Elementary School in December 2012.

“Where in God’s name is our backbone?” Biden said Tuesday evening, calling on the American people to “have the courage to deal with this and stand up to the [gun] lobbies.”