Vice President Mike Pence will invite the parents of murdered ISIS hostage Kayla Mueller to be guests at his debate with Sen. Kamala Harris (D-CA) on Wednesday night, Axios reports.

Carl and Marsha Mueller plan to attend the debate, bringing into focus Pence’s attempt to remind voters of Vice President Joe Biden’s weak record in the Obama administration on fighting ISIS.

The Department of Justice on Wednesday announced that two former British citizens who joined ISIS were charged with hostage-taking and abuse of Mueller and other Americans. Alexanda Amon Kotey, 36, and El Shafee Elsheikh, 32, were described as “The Beatles” of ISIS because of their English accents.

“The men also allegedly engaged in a prolonged pattern of physical and psychological violence against the hostages, including against American citizens James Wright Foley, Kayla Jean Mueller, Steven Joel Sotloff, and Peter Edward Kassig,” the Justice Department announced in a statement.

Carl and Marsha Mueller also delivered a heart-wrenching speech about their daughter during the Republican National Convention in August.

“President [Barack]Obama refused to meet with us until ISIS had already beheaded other Americans. To this day, we’ve never heard from Joe Biden,” Carl Mueller said. “Instead, the Obama administration hid behind policy so much that we felt hopeless when they kept us from negotiating to save Kayla’s life.”