(Fox News) -- The chief watchdog for the Department of Veterans Affairs confirmed Thursday that his office is working with federal prosecutors to weigh whether criminal charges are warranted in the health care scandal at a Phoenix VA facility.
VA acting Inspector General Richard J. Griffin, who spoke to lawmakers on Capitol Hill after VA Secretary Eric Shinseki delivered his first public testimony since the scandal broke, vowed to complete an "exhaustive review" and predicted it would be done by around August.
He said that review includes OIG criminal investigators as well as federal prosecutors from the U.S. Attorney's Office in Arizona and the Public Integrity Section of the Justice Department in Washington, D.C. They are working, he said, to "determine any conduct that we discover that merits criminal prosecution."
His comments come as some lawmakers call for heads to roll over the burgeoning controversy over patient deaths tied to delayed care. Facing calls for his resignation, Shinseki defended the VA system but vowed to get to the bottom of what happened in Phoenix and elsewhere, and take "all actions necessary."
"Any allegation, any adverse incident like this makes me mad as hell," Shinseki said Thursday before the Senate Veterans Affairs Committee.
Lawmakers, though, accused Shinseki of failing to act on repeated warnings about problems with the veterans health care system. He faced bipartisan criticism that his department is falling down on its vital obligation to care for America's veterans.
Sen. John McCain, R-Ariz. -- who represents the state where the scandal broke -- said the problems have created a "crisis of confidence."
"We should all be ashamed," said McCain, a Vietnam veteran.