American authorities face another complication as they build cases.
But more criminal indictments are probably not imminent, as prosecutors work to build cases.
And if British investigators won't build cases that way, American prosecutors and F.B.I. agents might.
Each has investigators, who build cases by tracing criminal backgrounds and relationships, debriefing prisoners and cultivating informants.
In virtually all usual circumstances, police and prosecutors are partners, working together to build cases against defendants.
They are looking to build cases against certain investors and "feeder" funds that funnelled their money to Mr Madoff.
Prosecutors often recommend lower sentences for defendants who cooperated with the government to build cases against others.
If he does help officials build cases against others, his ban could be reduced to eight years.
In Illinois, officers have used the sterilization requirement as a way to build cases against suspected dealers.
"You need to be able to penetrate these groups and build cases," said Samina Ahmed, director of the International Crisis Group in Pakistan.
Mr. Kelley says the time he put in quelling bar brawls and collaring burglars in the Hamptons helped him later in working with federal agents to build cases.
