WASHINGTON - In the year before her dismissal as San Diego's U.S. attorney, Carol Lam's Justice Department bosses griped about her in snide e-mails and strategized about putting her "on a very short leash."

Yet they gave no explanation when they finally kicked her out in December, Lam testified last month.

The e-mails, among more than 3,000 pages of documents released this week by the House Judiciary Committee, suggest officials grew frustrated by a prosecutor who had her own priorities and views.

In one exchange last July, a Justice Department official wrote that he was sad a top agency official was leaving. That official, Bill Mercer, wrote back suggesting other reasons for sadness.

"That Carol Lam can't meet a deadline," Mercer wrote, "or that you'll need to interact with her in the coming weeks or that she won't just say, 'O.K. You got me. You're right, I've ignored national priorities and obvious local needs. Shoot, my production is more hideous than I realized."'

Lam took over the San Diego office in 2002 with plans to raise the bar on immigration prosecutions to focus resources on violent criminals and repeat offenders - goals that put her at odds with political objectives inside and outside the Justice Department.

Justice Department officials have cited her record on immigration and gun prosecutions as a reason for letting her go. Democrats including California Democratic Sen. Dianne Feinstein, a member of the Judiciary Committee, are convinced there's more to it than that.

Lam won a bribery conviction from GOP Rep. Randy "Duke" Cunningham in 2005, and when she was fired she was prosecuting an ongoing corruption case, focused on Republicans, that grew from his plea.

This past May 10 Lam notified the Justice Department she'd be issuing search warrants for contractor Brent Wilkes and former CIA No. 3 Kyle "Dusty" Foggo.

The next day, Justice Department chief of staff Kyle Sampson, who resigned this month, wrote an e-mail to the White House counsel's office asking to discuss "the real problem we have right now with Carol Lam that leads me to conclude that we should have someone ready to be nominated on 11/18, the day her 4-year term expires."

Democrats want to question Bush adviser Karl Rove and other top administration aides under oath, and the Judiciary Committee chairman and top Republican have asked Sampson to appear voluntarily on Thursday. Feinstein plans to seek answers on ties between Lam's firing and the Cunningham case.

"I'd like to ask whether there is a connection, and on Thursday I will have an opportunity to ask that question and you can be sure it will be asked," Feinstein told reporters Friday. She said she has been considering summoning career prosecutors from Lam's office to talk to Congress.

Justice Department officials deny that public corruption prosecutions had anything to do with the dismissals of Lam and seven other U.S. attorneys. As early as January 2006, senior DOJ officials were putting Lam forward to the White House as a possible candidate for replacement when her four-year appointment expired in November.

By February 2006, an undercurrent of tension was evident in Lam's day-to-day relations with her immediate superiors.

On Feb. 8, Associate Deputy Attorney General Ronald Tenpas wrote an e-mail to Mercer complaining about having to deal with Lam and other U.S. attorneys on sentencing guidelines. "Please just shoot me at first sight and end the misery," he wrote.

Lam, meanwhile, was pleading with Tenpas to keep her sentencing program in place.

"Just not sure how much more bad news my folks can take," she wrote.

In May, Lam came under fire from Rep. Darrell Issa, R-Calif., for not prosecuting enough immigration cases. She called Tenpas to discuss how to respond, telling him that she was "sitting quiet rather than attempting to respond publicly by explaining the resource limitations," according to his account, but that she was "willing to change course if folks think that would be beneficial."

That same day, apparently without clearing it with Washington, Lam fired off a press release rebutting Issa's criticism.

Issa reacted with a scathing public letter that labeled Lam "incredibly disingenuous" - prompting Attorney General Alberto Gonzales' senior counsel Monica Goodling to remark: "The assault continues."

Later in the year, Lam met on the issue with Issa and GOP Rep. James Sensenbrenner of Wisconsin, then House Judiciary Committee chairman. She told her superiors the meeting was productive and even friendly. "Sounds like she handled it well and it was actually constructive," wrote Justice Department attorney Rebecca Seidel.

But by then Lam's fate might have been sealed.

On June 1, Sampson wrote to subordinates stressing the need to increase the department's immigration case filings and recommending having a "heart-to-heart" with Lam on this point.

Then, Sampson said, her superiors should: "Put her on a very short leash; if she balks on any of the foregoing or otherwise does not perform in a measurable way by July 15 (my date), remove her. AG then appoints new USA from outside the office."

By September, Lam's name began appearing on lists of U.S. attorneys the department planned to push out, and in December she was dismissed. Lam, meanwhile, was expressing "continuing dismay" both about her firing and the timing. Initially given a Jan. 31, 2007, deadline, Lam requested an extension citing "case related concerns," according to an e-mail from her DOJ handler to other officials.

Indictments charging Wilkes and Foggo with fraud and conspiracy were returned Feb. 13, two days before Lam officially resigned her post. Justice Department officials assured members of Congress that her departure would not affect the case.

On Feb. 26, Lam began working for San Diego-based wireless company Qualcomm Inc.

Associated Press Writer Allison Hoffman reported from San Diego.

Excerpts from Justice Department e-mails about Carol Lam:

"Please call me at your convenience to discuss the following: … The real problem we have right now with Carol Lam that leads me to conclude that we should have someone ready to be nominated on 11/18, the day her 4-year term expires." - May 11, 2006, e-mail from attorney general's chief of staff Kyle Sampson to White House counsel William Kelley.

"Has ODAG (Office of the Deputy Attorney General) ever called Carol Lam and woodshedded her re immigration enforcement? Has anyone?" - May 31, 2006, e-mail from Sampson to Associate Attorney General Bill Mercer.

"I don't believe so. Not that I'm aware of." - Mercer's reply.

"Have a heart-to-heart with Lam about the urgent need to improve immigration enforcement in SD. … Put her on a very short leash; if she balks on any of the foregoing or otherwise does not perform in a measurable way by July 15 (my date), remove her." - June 1, 2006, e-mail from Sampson to Mercer and Mike Elston, chief of staff to Deputy Attorney General Paul McNulty.

"This is so sad - I am not adjusting well to this change." - July 8, 2006, e-mail from Elston to Mercer.

"What that Carol Lam can't meet a deadline or that you'll need to interact with her in the coming weeks or that she won't just say, 'O.K. You got me, I've ignored national priorities and obvious local needs. Shoot, my production is more hideous than I realized." - Mercer, replying to Elston.

"We've granted 1-month extensions for Dan and Margaret, but not Carol - right?" - Jan. 5, 2007, e-mail from Sampson to Elston.

"David, I've really enjoyed every minute of my time as U.S. Attorney. Thank you for helping me have that experience, and for your valuable counsel over the years. … Warmest regards, Carol." - Feb. 16, 2007, e-mail from Carol Lam to Associate Deputy Attorney General David Margolis.