Issa: US marshals were last resort for subpoenas

“The use of the U.S. Marshals Service because DOE employees refused to voluntarily accept service via email is an another example of the lack of cooperation the committee has received in its investigation,” Hill added.

Issa is probing the embattled federal green energy loan program and focusing in particular on DOE officials’ use of their private email accounts, which Issa contends may have violated federal records laws.

Emails uncovered by the committee have shown that a number of DOE staff used their personal email accounts for discussions about the loan program, including Jonathan Silver, the former head of the loan program's office.