An electronic monitoring system tracking sex offenders, parolees and others shut down, leaving authorities in 49 states blind to offenders' movements for about 12 hours, authorities said Wednesday.
A system operated by Boulder, Colo.-based BI Incorporated unexpectedly hit its data storage capacity Tuesday morning, which blocked notifications to prisons and other corrections agencies on about 16,000 people being tracked, BI spokesman Jock Waldo said.
Tracking devices continued to record movement, but corrections agencies couldn't immediately view the data. The company has substantially increased its data storage capacity and hasn't heard of any safety issues, Waldo said. People being monitored were unaware of any problems.
"In retrospect, we should have been able to catch this," Waldo said.
In Wisconsin, prison officials had local police and probation agents detain about 140 sex offenders at local jails until the GPS tracking was back up and their whereabouts during the outage could be confirmed.
The offenders were never aware they weren't being tracked, Wisconsin Department of Corrections spokeswoman Linda Eggert said. The shut down affected about 300 people in Wisconsin, most of them sex offenders. She said the agency examined all their offenders' GPS movements and was certain the shut down didn't drive anyone to commit a new crime.
BI contracts with about 900 government agencies across the country for monitoring and notification services, including real-time monitoring and delayed notifications about offender whereabouts. The agencies vary widely, Waldo said, from state prison systems to local sheriff's departments to pre-trial service entities.
Along with GPS systems, the outage affected BI's in-home radio monitoring, typically used to check curfew compliance, and alcohol monitoring, which transmits data from home breathalyzer tests, Waldo said.
Before the shutdown, the company's database could hold 2.1 billion records, such as a GPS address or an alcohol reading, Waldo said. Company workers weren't monitoring how close the database was filling up when it exceeded the threshold Tuesday morning, he said.
The company spent Tuesday expanding the threshold to more than a trillion records. Waldo said staff will work to develop a system that can supply early warnings when as the database fills.
"People in our development group knew there was a threshold," Waldo said. "They've never in their careers ... seen a system hit such a database threshold. It speaks of the enormity of the data we collect."
Waldo said he was unsure of all the different types of offenders or defendants the company tracks. The agencies that use the company's systems decide who they want to track, and contract confidentiality clauses prevent BI from disclosing the information.
Wisconsin prison officials discussed the problems Wednesday, saying it was the first time they had faced such issues.
"Due to a system failure beyond our control, we faced a challenging and unprecedented event for our Electronic Monitoring Center," Wisconsin Department of Correction Secretary Rick Raemisch said in a statement. But thanks to the agency's emergency plan and cooperation from local law enforcement, "the situation was managed safely and efficiently with the number one priority being public safety," he said.
Eggert didn't know how many apprehension requests went out Tuesday or how many of the offenders remained in custody as of Wednesday.