The Justice Department has decided to prosecute savings and loan officials for specific, case-by-case violations rather than trying to pursue more complex criminal conspiracies to loot failed thrifts, Attorney General Richard Thornburgh and his top S&L prosecutor said yesterday.

The new strategy is meant to speed up enforcement and put wrongdoers in jail without tying up teams of FBI agents and prosecutors on massive cases that could take months to investigate and perplex jurors, said James Richmond, special counsel for financial institutions.

"The public would like us to tie the entire situation into one giant conspiracy," Richmond said, but "it's easier for the jury to understand" charges that a specific banking law was violated.

Thornburgh said the FBI is investigating 234 S&Ls for criminal violations and has probes underway at another 300 banks, credit unions and other financial institutions.

Congressional investigations of major S&L failures have discovered evidence of intricate chains of transactions in which borrowers and officials of several thrifts apparently worked together to siphon off millions of dollars and hide the losses from federal regulators. But for the most part, the Justice Department does not plan to prosecute those cases using the Racketeering Influenced Criminal Organizations (RICO) law, its most potent weapon against such conspiracies, Richmond and Thornburgh said at a lunch with reporters.

"It's just not productive," to try to tie together hundreds of transactions in an elaborate conspiracy case, Thornburgh said, because such cases take so long to prove that "you reach the point of no return" on the investment of resources required to bring them to trial.

Many of the criminal investigations of thrift fraud now underway are likely to lead to civil lawsuits to recover damages from thrift officials, their accountants, lawyers and others responsible for losses that end up being paid by taxpayers, the attorney general predicted.

"A very important part of the work is on the civil side as well," Thornburgh said.

In many cases the government will take both civil and criminal actions, seeking not only to put wrongdoers in jail but also to take away their ill-gotten gains.

It may be futile to seek civil damages from many thrift officials, because they've already gone bankrupt, the attorney general acknowledged.

Noting that the government does not have to prove criminal conduct in order to recover damages from thrift officers, directors and others, Thornburgh said, "Some of these cases, in the course of examining for criminal conduct, will shake out into civil cases," that are easier to prove.

The frequently quoted statistic that the Justice Department has received 21,000 criminal referrals from S&L investigations overstates the extent of S&L crimes, the two officials said. More than 16,000 of the cases came from Southern California, where an experimental case-tracking system produced a vastly increased number of complaints.

Most cases referred to the FBI for investigation are internally generated complaints from financial institutions themselves, not cases turned over to prosecutors by government regulators. Those referrals range from tellers suspected by their employers of slipping $20 into their pockets to executives accused by regulators of stealing millions, they noted. Nationwide, 83 percent of the cases involve losses of less than $25,000.

Yesterday, the Justice Department announced that the former chairman of a small-town Texas thrift has been indicted by a grand jury on 31 charges of bank fraud, embezzlement, giving false information to federal banking examiners and other charges. The indictments accused Alan Ross Rothery, who once headed Trinity Valley S&L of Trinity Valley of embezzling more than $4 million from the association, whose losses are projected to cost taxpayers $33 million.