The defendants were arrested over the summer on narrower charges, said Mark P. Ressler, an assistant United States attorney prosecuting the case.

Catherine E. Palmer, the assistant United States attorney prosecuting the case, did not return a call for comment yesterday evening.

The government will decide whether to seek the death penalty within the next three months, said Joseph Conway, the assistant United States attorney prosecuting the case.

"He paid $1 million for a $650,000 house," said Kenneth Madden, the assistant United States attorney prosecuting Mr. Catallozzi.

Rick Murad, the assistant United States attorney prosecuting the case, said the five brokers had agreed to plead guilty and cooperate in the investigation.

A federal grand jury is to begin hearing evidence in Houston on Aug. 16, said Michael T. Shelby, the United States attorney prosecuting the case.

If convicted, Mr. Naseem faces 25 to 33 years in prison, Joshua Klein, the assistant United States attorney prosecuting the case, said.

George A. Stamboulidis, the assistant United States attorney prosecuting the case, declined comment.

It seems George L. Bevan Jr., the assistant United States attorney prosecuting the case, anticipated such an argument.

The assistant United States attorney prosecuting the case, Todd Harrison, was one of the prosecutors who had interviewed Mr. Siraj.