The Pennsylvania Democrat now wants the Social Security Administration to expand and improve the initiative, which was launched last summer in five states and Washington, D.C., after a convicted killer on parole in Philadelphia allegedly kept several mentally disabled people captive while cashing their benefits checks.
In a letter to Social Security Commissioner Michael Astrue, Casey asks the federal agency to provide him with more information on goals, methods and a timeline for a revamped background check system. Casey's office provided a draft of the letter Sunday to The Associated Press.
About 5.6 million representative payees - those who receive benefits on behalf of people who cannot manage the funds themselves - handle $61 billion in Social Security payments each year for about 7.6 million beneficiaries.
"These beneficiaries need to know their representatives are individuals who can be trusted," Casey wrote.
A spokeswoman said Casey would discuss the letter further at a news conference on Monday. A Social Security spokesman could not be reached for comment.
Casey has been pushing the agency to be more vigilant in performing background checks on people who want to be designated as representative payees. He announced the pilot program in June, which includes Delaware, Maryland, Pennsylvania, Virginia, and West Virginia.
Under the program, Social Security offices in the Philadelphia region instituted a new policy that barred people convicted of certain crimes - including sex offenses, theft, forgery and abuse - from serving as payees. Applicants were asked specific questions about past criminal behavior and agency employees used an in-house database to cross-check convictions.
Through Jan. 23, 100 people were rejected from becoming payees, Casey said.
The stepped-up effort stems from the 2011 arrest of parolee Linda Weston of Philadelphia.
Weston faces state and federal charges for allegedly tricking mentally disabled people into making her their payee while she kept them captive in squalid basements, attics and closets. Federal prosecutors allege she caused the deaths of two people through abuse and neglect.
Weston, 52, maintains her innocence, and has pleaded not guilty to the state charges.
Weston served prison time decades ago for starving a man to death, but her past went undetected for years while she allegedly profited from other people's government benefits. Federal law prohibits anyone who has been incarcerated for more than a year from becoming a payee.
A recent inspector general's report indicated the Social Security Administration was not effectively enforcing the law, instead relying on applicants to self-report the information.
Social Security Administration spokesman Mark Hinkle has previously said key stumbling blocks to more vigorous screening are the agency's lack of access to government databases with criminal background information and a dearth of staff to perform checks on each applicant.
Casey introduced legislation in November 2011 that would give the agency access to better criminal databases, including the one used by the FBI. He said the Social Security Administration's in-house records are not comprehensive enough. Congress did not act on the bill last session, and Casey plans to reintroduce it.