Attorney General Alberto Gonzales and Marshals Service Director Ben Reyna are expected to announce the results of the unprecedented coast-to-coast sweep at a news conference Thursday afternoon.
Among the 10,340 people captured between April 4 and April 10 are 162 accused or convicted of murder, 638 wanted for armed robbery, 553 wanted for rape or sexual assault, 154 gang members and 106 unregistered sex offenders.
Some targets were considered especially dangerous. In one case, an armed man was found in a cave under a trap door in his kitchen floor.
Some fugitives had escaped from prisons and jail, some had been released on bond and others had been named in criminal warrants but disappeared or failed to appear as ordered.
"We're really amazed. We had no idea we'd apprehend more than 10,000 bad guys," said one federal law enforcement official who asked not to be identified. "We didn't know what to expect, but the response from law enforcement personnel everywhere was truly amazing."
A comparison with Marshals Service arrests in fiscal 2004 gives an idea of the scope of this month's sweep. For that year, U.S. Marshals caught more than 36,000 federal felons, and Marshals-led task forces also arrested more than 31,600 people wanted on state and local felony warrants, according to the U.S. Marshals Web site.
Some fugitives captured this month were less dangerous, and more old-fashioned than others. In cases described by an official as "the new and the old," the fugitives captured included operators of two methamphetamine labs and an illegal alcohol-producing still.
Fugitives were tracked in every state, plus Puerto Rico and Guam, officials said.
Officials insist the operation was strictly designed to carry out law enforcement objectives but acknowledge the scope of the operation was expected to prompt positive publicity.
In addition, one official said the operation, originally considered for later this spring, was timed in part to coincide with "Crime Victims Rights Week."
"One thing this does is demonstrate support for victims of all these crimes. When these fugitives are captured, it helps bring closure," said the law enforcement source.
The mission was dubbed "Operation FALCON", which officials say is an acronym for "Federal and Local Cops Organized Nationally."
"Just about anybody with a badge and a set of handcuffs was asked to help out, and they did," said another official familiar with the operation.
More than 3,000 law enforcement officials searched for fugitives, and as many as 10,000 may have helped at least part-time, officials said. The raids were coordinated by five national fugitive task forces and 83 district task forces led by the U.S. Marshals Service.
Among 25 federal agencies enlisted to help were the Bureau of Alcohol, Tobacco, Firearms and Explosives; the Drug Enforcement Agency; the Federal Bureau of Investigation, the Secret Service and even Inspector General investigators for the Department of Housing and Urban Development and the Social Security Administration. HUD's interest was related to fugitives with housing benefits, and some of those on the run received Social Security benefits, sources said.
Much of the law enforcement muscle came from 206 state law enforcement agencies, 302 county sheriffs' departments, and 366 city police departments.