Washington ? A Secret Service document written shortly after the 1995 Oklahoma City bombing described security video footage of the attack and witness testimony that suggested Timothy McVeigh may have had accomplices at the scene.

“Security video tapes from the area show the truck detonation 3 minutes and 6 seconds after the suspects exited the truck,” the Secret Service reported six days after the attack on a log of agents’ activities and evidence in the Oklahoma investigation.

A Secret Service agent testified Monday in the trial of conspirator Terry Nichols that the log does, in fact, exist but that the government knows of no videotape. The log that the information was pulled from contained reports that were never verified.

Stacy A. Bauerschmidt, assistant to the special agent in charge of the agency’s intelligence division, said the timeline was an internal log developed to help locate personnel lost in the bombing and determine whether the agency was a specific target of the attack.

Reports may have been based on mere speculation, and the agency does not vouch for it reliability, she said.

The document, if accurate, is either significant evidence kept secret for nine years or a misconstrued recounting of investigative leads that were often passed by word of mouth during the hectic early days of the case.

“I did not see it,” said Danny Defenbaugh, the retired FBI agent who ran the Oklahoma City probe. “If it shows what it says, then it would be significant.”

Lone driver?

The government has maintained for years that McVeigh parked the Ryder rental truck carrying a massive fertilizer bomb outside the Alfred P. Murrah federal building and left alone in a car he had parked around the corner.

The only video prosecutors introduced at trial showed the Ryder truck without any visible passengers as it passed a security camera inside a high-rise apartment building a block away from the Murrah building.

But the Secret Service log reported on April 24 and April 25, 1995, that there was security footage showing the Ryder truck pulling up to the Murrah building. The log does not say where such video came from.

An entry on April 24 reported that the security video was consistent with a witness’ account that he saw McVeigh’s getaway car in the lead before a woman guided the truck to its final parking spot in front of the Murrah building.

“A witness to the explosion named Grossman claimed to have seen a pale yellow Mercury car with a Ryder truck behind it pulling up to the federal building,” the log said. The witness “further claimed to have seen a woman on the corner waving to the truck.”

A Secret Service agent named McNally “noted that this fact is significant due to the fact that the security video shows the Ryder truck pulling up to the Federal Building and then pausing (7 to 10 seconds) before resuming into the slot in front of the building,” the log said. “It is speculated that the woman was signaling the truck when a slot became available.”

Defenbaugh said the FBI had talked to several witnesses suggesting two people had left the truck, but prosecutors never introduced the scenario at trial because it couldn’t be corroborated.

Defenbaugh said the FBI kept a log similar to the Secret Service document inside the Oklahoma City investigation command center that might help solve the mystery of the video. Justice officials declined to discuss documents, citing the ongoing Nichols’ trial.

In addition to the witness mentioned in the Secret Service document, a woman working in Murrah’s Social Security office who was rescued from the rubble and a driver outside the building both reported to the FBI seeing two men leave the truck, according to government documents.