Registered sex offender Anthony Sowell was able to hide six decomposed bodies in his Cleveland home from officials who routinely checked in on him, calling into question the effectiveness of the probation and parole system.
There are too few officers checking on a growing registry of sex offenders that often tops 100 for each officer to keep an eye on, at times giving the same level of scrutiny to offenders who had one-time flings with a minor to dangerous predators.
"The system is broken in the sense that we have a lot of people on sex registries and while it gives us a list of people who might be involved in crimes, there are so many people on those lists that they're overly inclusive," said Jonathan Simon, the associate dean for Jurisprudence and Social Policy at UC Berkeley's School of Law. "[These lists] don't give authorities the chance to select those who are the higher risks," said Simon.
Sowell, 50, was last visited by officials on Sept. 22, more than a month before it was discovered that there were six women dead in the home, five of whom are believed to have been strangled.
Investigators said some of the bodies had been in Sowell's home for months, possibly years.
Sheriffs deputies say they were not allowed to go into Sowell's home on their routine house checks because Sowell, who spent 15 years in prison for choking and raping a 21-year-old woman in 1989, was not on probation or parole.
Sowell's house was only entered by authorities after a woman in the neighborhood reported having been raped inside the home, giving police reasons for a search warrant.
In September, California Inspector General David Shaw launched an investigation into how several different state parole officers failed to discover that accused kidnapper Phillip Garrido was able to keep Jaycee Dugard hidden for 18 years. Dugard was discovered in Garrido's Antioch, Calif., yard in August.
Shaw told ABCNews.com at the time that Garrido, 58, had five or six different state parole officers assigned to check up on him over the nearly two decades he held Dugard in his back yard.
The officers checking on Garrido at any one time had a case load that included at least 39 other offenders, according to public records.
Steve Austin, a correctional program specialist at the National Institute of Corrections, told ABCNews.com that these two cases highlight the problems that exist in the parole and probation system.
"A lot of times the resources are so limited that the parole agencies aren't doing the kind of checks that the public might think they are," said Austin. "These parole officers have such large caseloads they aren't able to do intricate checks of these offenders' homes."
Anthony Sowell Case Highlights Problems With Sex Offender Registries
In Garrido's case, officers were called to the home in 2006 when neighbors complained that there might be people living in the backyard. Officers reportedly met with Garrido in his front yard and determined everything was fine, a conclusion that the Contra Costa sheriff's office later took responsibility for.
Austin said that parole officers simply knocking on the doors of offenders and moving on to the next name on their list is not unusual.
"Sometimes it's an issue that these officers are limited in what they're allowed to do and other times they don't have the resources to spend the time doing more than just knocking," said Austin.
Jonathan Simon, the associate dean for Jurisprudence and Social Policy at UC Berkeley's School of Law, said that the long lists sex offenders like Garrido and Sowell are put on are often ineffective in preventing future crimes from being committed.
"The system is broken in the sense that we have a lot of people on sex registries and while it gives us a list of people who might be involved in crimes, there are so many people on those lists that they're overly inclusive," said Simon. "[These lists] don't give authorities the chance to select those who are the higher risks," said Simon.
When 7-year-old Somer Thompson disappeared in northern Florida last month and was found days later in a Georgia landfill, police fanned out to interview the registered sex offenders in the area. There were 150 registered sex offenders within a nine mile radius of Somer's house.
Simon said another problem with the system is that many officers who follow offenders for years tend to get lax in their surveillance after making house calls for years.
"How do you spot [a criminal] and whose behavior on the surface doesn't put them far outside the norm in their community?" said Simon.
The Associated Press contributed to this report