Updated

After two cases of alleged criminals going door-to-door to take surveys, Alabama Sen. Richard Shelby said Monday that the U.S. Census Bureau must do more to prevent hiring census takers with a criminal background.

In a letter to Commerce Secretary Gary Locke sent Monday, Shelby wrote that when he asked Locke during a Senate hearing last year about guidelines to disqualify applicants, including sex offenders and people who've committed crimes against children, he was told the measures would ensure "each applicant is an acceptable risk to collect census information from residents of a community as a representative of our government."

"It is inconceivable that the Census Bureau could be so poorly managed as to hire a convicted sex offender to go door-to-door to collect personal information," Shelby said. "Clearly, Mr. Secretary, your guidelines are not working."

The letter followed news last week that a sex offender in New Jersey had spent two weeks in May interviewing residents while carrying around an official Census badge, bag and list of residents who hadn't returned their surveys.

Frank Kuni reportedly had used fake documents under the name Jamie Shephard to pass an initial name check and receive four days of training.

But an alert resident recognized the 47-year-old from the state's Internet sex offender registry.

Kuni, who was charged with using a fraudulent document to get government ID, was fingerprinted during his first day of training but when Census officials learned on the last day of training that Kuni had been flagged for a previous arrest, he was already out the door with his assignment, Fernando E. Armstrong, director of the U.S. Census Bureau's Philadelphia region, told the Courier News.

He was arrested four days later.

"From our perspective, the process that was put in place and has been used across the country worked in this case," Armstrong told the newspaper, acknowledging that an earlier return of the background check would've prevented Kuni from reaching the street.

In a separate case in Indiana, a volunteer census worker named Daniel Miller allegedly raped and beat a 21-year-old physically handicapped woman after returning to her home in the middle of the night following an interview earlier in the day.

Shelby said that during the 2000 Census, one in four of the 930,000 applicants for the temporary jobs were flagged by the FBI and prevented from working.

"The Census Bureau spent $2.5 million on a Super Bowl advertisement to encourage participation in the Census and has gone to great lengths to assure Americans that they should open their doors to Census workers. The lack of adequate oversight is unacceptable," Shelby wrote.

"What is even more objectionable is that it does not appear from public statements on the incident that the Census Bureau admits fault or even acknowledges that their screening procedures are not working," he wrote.