The son of a business executive killed by a hit man told a congressional panel investigating FBI use of informants today that the bureau let him down by shielding mobsters while they continued their deadly crimes.

"Forgotten in all of this are the people the agents are supposed to serve -- people like my father," David Wheeler said.

His father, Roger Wheeler, was shot between the eyes by hit man John Martorano in 1981. His family has filed a wrongful-death lawsuit against the government, claiming that the FBI knew its mob informants were committing crimes and let them go unprosecuted.

"Where there was once trust, there is now fear, and that is a loss we cannot afford," Wheeler told the House Government Reform Committee, which began a two-day hearing here today.

Roger Wheeler, owner of World Jai Alai in Miami, was 55 when he was gunned down in Tulsa. Wheeler was killed after gang leader James "Whitey" Bulger learned that Wheeler suspected the gang of skimming his company's profits.

In May 2001, Martorano pleaded guilty to murdering Wheeler. Wheeler's slaying is one of 21 in which Bulger faces charges. Bulger disappeared in 1995 after being tipped off by his FBI handler that he was about to be indicted.

The House panel, led by Rep. Dan Burton (R-Ind.), wants to talk to Bulger's brother, William Bulger, president of the University of Massachusetts and former president of the state Senate. He has been subpoenaed to appear Friday.

William Bulger's attorney, Thomas Kiley, said there may be grounds to quash the subpoena because of a leak this week of testimony his client gave to a grand jury.

In the testimony, obtained by the Boston Globe, William Bulger said he spoke with his brother shortly after he went on the run. He said he didn't feel compelled to help authorities find his brother and did not urge him to surrender.

Kiley said the leaked testimony made his client's appearance at the hearing unfair.