At first, investigators thought some particular incident had caused the cluster of defects.

Some investigators think that this sparked the move to the attacks.

The attacks were so severe that investigators initially thought the couple had been shot.

But investigators now think that the man misled the police.

He said that investigators in some cases thought they had more to gain by following the money rather than impounding it.

But he declined to explain why investigators thought so.

Also, it said, the investigators in the trials had not thought the drug caused any of the deaths.

The principal investigators of both studies think they know the problem.

But some investigators have long thought he might know something about it, though they had not heard from him.

Two weeks ago, the investigators thought they had identified a third cell, of six or seven men, that was preparing for another attack.