Senator Joe Manchin (W.

Va.) is joining a House Judiciary committee that is investigating the FBI’s handling of a gun trafficking investigation that led to the death of a West Virginia sheriff’s deputy.

The House Judiciary Subcommittee on Crime, Terrorism, Homeland Security and Governmental Affairs has asked Attorney General Jeff Sessions to testify before the panel.

The subcommittee’s chairman, Representative Adam Schiff (Calif.), on Tuesday asked Sessions whether the FBI used “any form of coercion” to coerce witnesses.

Manchin is a Democrat and one of the committee’s top lawmakers.