Pottstown, Pa. ? A veteran FBI agent killed a week ago while pursuing a trio of bank robbery suspects in central New Jersey was eulogized Thursday as a dogged investigator and role model to legions of colleagues.

At least 2,000 people, including FBI Director Robert S. Mueller III and U.S. Attorney General Alberto Gonzales, came to an arts center auditorium here for the funeral of Special Agent Barry Lee Bush. The crowd was so big hundreds had to listen to a broadcast of the services from a nearby building.

“By his actions, he probably saved the lives of innocent people,” former FBI director Louis J. Freeh told the throng. “You can’t quantify that.”

Bush, 52, who played a key role in several high-profile cases during his 19-year FBI career, was fatally shot April 5 while he and other agents tried to capture a group of suspected bank robbers in Readington Township, N.J. The FBI said Bush may have been accidentally shot by another agent during the confrontation outside a PNC bank.

He was the 51st FBI agent killed in the line of duty.

“If you were an FBI agent and you worked with Barry Bush, you became a better agent,” said Special Agent David Jon Harvey, who said he was a member of the team that responded to the bank robbery.

Harvey said he wished he had told Bush, who had begun to talk of retirement recently, to skip the stakeout, but that it wouldn’t have made much difference.

“He probably would have called me some names, kicked the trash can and said, ‘I’m coming,'” Harvey said.

Mourners filed past Bush’s closed, flag-draped casket, surrounded by flowers and next to a table with pictures of him and his family.

An internal investigation into the shooting is under way. The FBI said Bush may have been struck when a fellow agent’s weapon discharged accidentally. The FBI has declined to provide specific details.

However, two law enforcement officials with knowledge of the investigation said the shooter may have mistaken Bush for a suspect. The officials spoke on the condition that they remain anonymous because they were not authorized to talk about the investigation.

Bush, who lived near Easton, is survived by a wife and two children.