The federal agents laid a photo lineup before the custodian, asking her if she could spot the man she had seen the previous week suspiciously lurking around the downtown Omaha federal building.

Suddenly the woman became visibly upset when her eyes landed on one of the mug shots.

She pointed to it and said through tears, "I have no doubt, that's the guy."

The woman was pointing to a mug shot of Timothy McVeigh.

In the wake of the deadly Oklahoma City bombing, reports circulated that McVeigh and an accomplice a week before may have staked out the old federal building at 15th and Dodge Streets in Omaha, perhaps for a follow-up attack.

At the time, law enforcement officials called the reports inconclusive at best. Ultimately, McVeigh's trial for what at the time was the deadliest terrorist attack on U.S. soil left the question unanswered.

Now 10 years later, as the nation observes the anniversary of the Oklahoma City bombing, the law officer who at one point headed the investigation of the Omaha incident speaks openly about it for the first time.

He also offers a personal opinion on whether McVeigh was here, one based on "a cop's intuition."

"Unless somebody shows me evidence to the contrary, it's my feeling then and now that it's very likely Tim McVeigh was one of the intruders in our building the week before," said Mark James, who in 1995 headed the Omaha office of the federal Bureau of Alcohol, Tobacco and Firearms.

James now heads the Department of Public Safety for the State of Missouri.

He said the janitor's physical reaction to McVeigh's photo, plus similarities between McVeigh and the police sketch of the Omaha intruder - minus the obvious wig the janitor said the intruder was wearing - are too much to ignore.

Even if it wasn't McVeigh in Omaha, James says, there were too many coincidences and other McVeigh connections to make him conclude that the suspicious incident at the Omaha federal building had nothing to do with the Oklahoma City conspiracy.

Those connections include McVeigh's use of an Omaha man's name and a fake Omaha address when he rented the Ryder truck used to bomb the federal building, and similarity in the description of the second Omaha intruder to that of "John Doe No. 2," a possible McVeigh accomplice whom federal investigators were never able to identify.

"It's not up to the level of a smoking gun. But when you add all those things together, it's more than just mere coincidence," James said.

James well remembers Monday, April 17, 1995.

Two officers in the ATF office were talking about conversations they had the week before with two different janitors, each about an intruder the janitor had encountered in the building at an odd hour.

Both intruders, who were in the building one or two days apart, asked odd questions: What floor is the ATF office on? How many officers are there? How well-armed are they?

It was two days before the Oklahoma City bombing. There was no obvious cause for alarm.

But still, the reports made the hair on the back of James' neck stand up. That only happened two other times in his law enforcement career-both when suspects pointed guns at him. He sensed a threat.

James asked the agents to re-interview the custodians in detail and take them to Omaha Police Headquarters to have sketches made.

James recalls that the sketches came back on April 19 - the same day a then-unknown man detonated a massive truck bomb in Oklahoma City, killing 168. The Omaha incident suddenly took on more urgency.

Within two days, McVeigh - who had been arrested the day of the bombing during a traffic stop - had become the prime suspect in Oklahoma City.

James said the ATF officers quickly saw the resemblance between the man in custody in Oklahoma and long-faced man in one of the Omaha sketches.

The man had glasses and long scraggly hair, nothing like McVeigh's military crew cut. But the janitor - a young woman in her 20s - who had encountered the intruder in a stairwell had said he appeared to be wearing a wig, describing his hair as "lifeless."

The man in the second Omaha police sketch looked remarkably like "John Doe No. 2," the drawing of a McVeigh accomplice seen with him numerous times in the week before the bombing.

The woman janitor was then brought back to look at a photo lineup. She said at the time she had not seen any TV images of the alleged bomber. James will never forget her reaction to McVeigh's photo.

"I've interviewed hundreds of people, and this was a spontaneous emotional reaction," he said. "It was not rehearsed."

The woman was interviewed again later, when investigators found wigs in the Kansas home of Terry Nichols, another bombing conspirator. She said none of the wigs matched the one she saw. To James, that increased her credibility. She wasn't fingering McVeigh to get attention.

The Omaha ATF and FBI offices would be asked to check out numerous other Omaha connections. Those included McVeigh's use of a fake ID with the name Robert Kling and a phony Omaha address. McVeigh also said he would be returning the rental truck to a Ryder outlet in Omaha.

At the time, there were two Robert Klings in Omaha. FBI officials have said both were interviewed and cleared.

James, however, said a canvass of the neighborhood around one of the men's homes revealed some intriguing details. One neighbor reported seeing men wearing Army fatigues carrying duffel bags in and out of the house.

The FBI investigation in the end found no other evidence to corroborate McVeigh's being in the Omaha federal building. James said he knows there are FBI officials who have looked at what is known about McVeigh's movements the week before the bombing and concluded that he could not have been in Omaha.

Still, James said, from what he has seen there are gaps in the shadowy McVeigh's movements. Junction City, Kan., the town from which McVeigh operated, is less than a four-hour drive from Omaha.

Now that McVeigh has been executed, James said, we probably never will know what his intentions were when he was arrested 10 years ago today driving north out of Oklahoma City.

"I wonder if they had a more grandiose plan to do more than one building?" he asks. "Had he not been caught driving away from Oklahoma City, where was he headed next?"