TUCSON — Jared L. Loughner wanted change back from a $20 bill that he used to pay for a taxi ride to a Safeway store here, according to the manager of the taxi company.
His demeanor was so unremarkable that the driver thought nothing of walking into the store with Mr. Loughner to get change, and did not know that a shooting rampage occurred at the scene until many hours later.
“No red flags went up,” said Joe Acosta, the general manager of the taxi company, AAA Full Transportation. “The customer got his change, our driver got his fare and left, and that’s it.”
That account of the taxi ride provides small but telling new details on what preceded the shooting.
It might suggest, for example, that Mr. Loughner, 22, planned or hoped to escape, and would need the money, after what police said was a deliberate attack on Representative Gabrielle Giffords.
Or it could be one more element of his unsettled mental state on the morning of the attack — that getting his change was somehow important before, as police say, he opened fire with a 9 millimeter Glock pistol at a constituents meeting.
Mr. Acosta said the driver, John Marino, who was questioned by the F.B.I. and Pima County sheriff’s officers at the taxi company on Sunday morning, was not taken into custody and has declined to speak to any reporters.
“He was like, ‘I really don’t need this,’ ” Mr. Acosta said.
Mr. Loughner’s state of mind, in the weeks and months before the shootings and perhaps especially on Saturday morning itself, has emerged as a major subtext of the investigation here, as the authorities try to understand his motive and mental state.
But the environment of Tucson — the light traffic on a Saturday morning, and the volume of taxi calls — perhaps played a role as well in what, according to Mr. Acosta’s secondhand account, seemed at the time to be nothing more than a young man’s calm ride to the grocery store.
“Since the volume wasn’t that heavy on Saturday, he was picked up moments after the call was placed,” Mr. Acosta said. “And a few minutes later he was at the Safeway.”
The driver, Mr. Acosta added, “treated it like it was a normal run — nothing out of the ordinary.”
Mr. Acosta said that Mr. Marino noticed sirens coming in the opposite direction as he was heading to pick up his next fare on Saturday morning, but thought nothing of it until the next day, when security camera images showing him walking into the store with Mr. Loughner became part of the police investigation.
