Updated

The FBI has found a long-lost transcript of the 1955 murder trial of two Mississippi men accused of killing Emmett Till (search), one of the most infamous crimes of the civil rights era.

"We found a copy of a copy of a copy," Robert J. Garrity Jr., agent in charge of the Jackson office, said Monday. "We had to painstakingly go through it and retype it."

Garrity wouldn't say where the transcript, missing for decades, was found.

The Justice Department announced plans last year to reopen the investigation into Till's death, citing information including a documentary that claimed to have found new evidence.

The 14-year-old black youth, who was raised in Chicago, was visiting an uncle in the small Mississippi Delta town of Money in 1955 when he was abducted from the home and killed, reportedly for whistling at a white woman.

No autopsy was performed before Till was buried, and the FBI is planning to exhume his body from a Chicago-area cemetery within the next few weeks for an autopsy to confirm the identification of the badly mutilated body and determine the cause of death.

Two white men charged with Till's murder — store owner Roy Bryant and his half brother J.W. Milam — were acquitted by an all-white jury but later confessed to Look magazine. They have since died. Legal experts say a transcript is key to putting together the case against any living suspects.

The FBI said DNA tests done on Till's body will be matched by swabs taken from family members. The tests hope to verify the identity of the body, which Till's mother was able to identify only by a ring on the youth's finger.

In a letter mailed to media outlets last week, Garrity said the government's decision to exhume Till's body is vital to the investigation.

"The investigation has now progressed to a point where the exhumation and examination of Till's remains are essential," Garrity said.

The slaying took place nine years before the Civil Rights Act of 1964 (search) gave the FBI authority to investigate civil rights abuses.

Garrity says the FBI has been looking for residents of Money who had a connection with the killing and following up on witness accounts.