The 48-year-old Walsh was an assistant federal prosecutor in Los Angeles and a member of the team that investigated and prosecuted Charles Keating.
Walsh, who grew up in Colorado, returned to Colorado in 1999 and joined a Denver law firm handling antitrust, securities and environmental cases.
In announcing Walsh's confirmation Friday, Sen. Mark Udall called Walsh "eminently qualified" and "one of the most civic-minded people I know."
President Barack Obama nominated Walsh in April. Obama's first nominee, Gov. Bill Ritter's deputy chief of staff Stephanie Villafuerte withdrew her name in December.
