IMPEACH BUSH

(CBS) The Department of Veterans Affairs came under fire again Monday, this time in California federal court where it's facing a national lawsuit by veterans rights groups accusing the agency of not doing enough to stem a looming mental health crisis among veterans. As part of the lawsuit, internal e-mails raise questions as to whether top officials deliberately deceived the American public about the number of veterans attempting and committing suicide. CBS News chief investigative correspondent Armen Keteyian reports.

In San Francisco federal court Monday, attorneys for veterans' rights groups accused the U.S. Department of Veteran's Affairs of nothing less than a cover-up - deliberately concealing the real risk of suicide among veterans.

"The system is in crisis and unfortunately the VA is in denial," said veterans rights attorney Gordon Erspamer.

The charges were backed by internal e-mails written by Dr. Ira Katz, the VA's head of Mental Health.

In the past, Katz has repeatedly insisted while the risk of suicide among veterans is serious, it's not outside the norm.

"There is no epidemic in suicide in VA," Katz told Keteyian in November.

• Follow up: VA Struggles With Vets' Mental Health.
• How we got the numbers behind the story.
• VA Doctor on Veteran Suicides.
• FYI: Suicide Risk Resources and Warning Signs.

But in this e-mail to his top media adviser, written two months ago, Katz appears to be saying something very different, stating: "Our suicide prevention coordinators are identifying about 1,000 suicide attempts per month among veterans we see in our medical facilities."

Katz's e-mail was written shortly after the VA provided CBS News data showing there were only 790 attempted suicides in all 2007 - a fraction of Katz's estimate.

"This 12,000 attempted suicides per year shows clearly, without a doubt, that there is an epidemic of suicide among veterans," said Paul Sullivan of Veterans for Common Sense.

And it appears that Katz went out of his way to conceal these numbers.

First, he titled his e-mail: "Not for the CBS News Interview Request."

He opened it with "Shh!" - as in keep it quiet - before ending with "Is this something we should (carefully) address … before someone stumbles on it?"

On Monday, CBS News showed the e-mail to Rep. Bob Filner, D-Calif., who chairs the House Committee on Veterans Affairs.

"This is disgraceful. This is a crime against our nation, our nation's veterans," Filner told CBS News. "They do not want to come to grips with the reality, with the truth."

And that's not all.

Last November when CBS News exposed an epidemic of more than 6,200 suicides in 2005 among those who had served in the military, Katz attacked our report.

"Their number is not, in fact, an accurate reflection of the rate," he said last November.

But it turns out they were, as Katz admitted in this e-mail, just three days later.

He wrote: there "are about 18 suicides per day among America's 25 million veterans."

That works out to about 6,570 per year, which Katz admits in the same e-mail, "is supported by the CBS numbers."

In an e-mail late Monday to CBS News, Katz wrote that the reason the numbers were not released was due to questions about the consistency and reliability of the findings - and that there was no public cover up involved.