Clapper and other senior administration officials cited the ACES program in a February 2010 report laying out the government's plan for improving security clearances. Former Adm. Mike McConnell, who headed the DNI during the Bush administration, was an early proponent of electronic monitoring research.
"If one guy has a Jaguar on a (government) GS-12 salary, that's a red flag," McConnell said.
According to project documents, ACES links to up to 40 databases. While many are government and public data streams already available, ACES also taps into the three major credit agencies — Experian, Equifax and Trans Union.
One former official familiar with ACES said researchers considered adding records from medical and mental health files but due to privacy concerns left that decision unresolved for policy makers.
The government's inability to review information from local police reports, his employer, family and personal health records was cited as a glaring weakness in background checks on computer specialist Aaron Alexis, who fatally shot 12 people at the Washington Navy Yard last September before killing himself.
The Alexis case and the Snowden disclosures raised concerns about the flawed or inadequate work of outside contractors in background checks.
A federal official acknowledged that outside contractors would likely be used to support electronic monitoring. It was not clear whether Northrop Grumman, the company that helped develop ACES, would have a role in its government-wide deployment.
Critics worry about the potential misuse of personal information. Private contractors supporting the monitoring system would have access to sensitive data. Credit agencies and other outside data sources would know the identities of government employees under scrutiny.
"The problem is you're spreading all this private data around to more and more people, both inside and outside," said David Borer, general counsel for the American Federation of Government Employees.
The union represents federal workers with top secret clearances but recently joined in a lawsuit against the government to prevent lower-level employees from being reclassified into jobs requiring clearances.