Matthew Stuart, 23, said he then threw the revolver and purse from a railroad bridge over the Pines River.

Gun Missing From Store

A law-enforcement official said today that Charles Stuart might have gotten the gun from a safe at the Kakas & Sons fur shop on fashionable Newbury Street, where he was the manager. The co-owner of the shop, Jay Kakas, reported a silver revolver missing, but only last Friday after Mr. Stuart committed suicide.

The Boston Globe reported today that Mr. Kakas had bought the gun 10 years ago but had stored it in a safe and forgotten about it after the store hired its own armed security.

Reached by telephone today, Edward Kakas, the other co-owner of the store, said the missing gun was a .38-caliber revolver, but he would not comment on other questions, including why neither he nor his brother had reported it missing earlier.

A senior law-enforcement official said today that the investigation would have been much easier and would not have incorrectly identified William Bennett, a 38-year-old black man with a criminal record, as the Stuarts' assailant if the police had known earlier about the missing gun.

In fact, the official said, he was amazed at how many people were now coming forward, after Mr. Stuart's death, with clues that would have facilitated the investigation. Several relatives or friends of Mr. Stuart, for example, have now reported that well before the October shooting he had suggested killing his wife. It has also become clear that several of Mr. Stuart's three brothers and sisters had known about his involvement in the killing before Matthew Stuart went to the police last week.

Life Insurance Policies

A spokesman for the John Hancock Mutual Life Insurance Company, Richard P. Bevilacqua, said the company had paid out $82,000 in insurance to Mr. Stuart in December for a policy that his wife held at the publishing company where she worked as a lawyer. The payout was made with unusual speed at the request of Mrs. Stuart's employer, the Cahners Publishing Company, he said, and the amount was twice her salary, because her death was considered accidental.