Formers employees of contractor USIS claim they were given dozens of cases to review on very short deadlines, The Washington Post reported Friday.
One former worker said she had to work as many as 10 cases a day, requiring her to drive from one end of Los Angeles to the other to complete interviews.
Another former worker described the work environment at USIS as "like wink, wink, do this as fast as humanly possible. There was this intense pressure to do more and faster."
One former employee expressed concern about the rush to approve even top-secret clearances.
"There's just not a lot of paying attention to potential red flags and that sort of thing," the former employee said.
All the former workers spoke on condition of anonymity to avoid upsetting their former employer.
No evidence has emerged the company, based in Falls Church, Va., cut corners in approving security clearances for Snowden, who leaked secrets he encountered while working for the National Security Agency, or Alexis, who shot and killed 12 people on Monday. However, a number of former ISIS workers have been charged with falsifying records and the company is being investigated about the thoroughness of its work.
USIS, with about 7,000 employees, handles nearly half of all contracted background checks for the Office of Personnel Management, which processed nearly 2.3 million investigations in 2012.
USIS has been paid $334 million for its work so far this year.