They looked like a father and son -- always smiling happily -- when they arrived to work out at the Silver Spring YMCA. They inquired about vertical window blinds at an Aspen Hill store. They had a pizza delivered to their room at a Spotsylvania County motel. There were sightings at a Northwest Washington shelter, a Shoney's in Hagerstown, Md., and a sandwich shop in Baltimore.

In the aftermath of arrests in the sniper case, investigators have heard from dozens of people who believe they caught a glimpse of the suspects going through what appeared to be the mundane routines of daily life during the very days the shootings took place.

On Oct. 7 -- hours after a 13-year-old was critically wounded at his Bowie middle school -- two employees of a Baltimore Subway sandwich shop say they served John Allen Muhammad a brownie. On Oct. 11 -- 11 hours after a shooting just across the street at a Spotsylvania Exxon station -- a deliveryman says he was tipped a single penny when he took a large pizza to a room occupied by Muhammad and John Lee Malvo at the Econo Lodge.

Ten days later, on Oct. 21 -- the evening before a bus driver apparently became the attackers' final victim -- the manager of an Outback Steakhouse in Aspen Hill believes Muhammad was the man who waved off alcohol and settled for water with his dinner. The next day -- hours after the bus driver's death -- a Silver Spring YMCA clerk recalls that Muhammad and Malvo begged for a waiver of the $3 fee for a workout.

The day after that -- less than seven hours before the two men were arrested as they slept in their car at a Frederick County roadside rest stop -- a waitress at the Hagerstown Shoney's says Muhammad asked for directions to Harrisburg, Pa., as he paid his dinner bill.

The trail of dead and wounded left by the sniper attacks since the mayhem began Oct. 2 has been well established. Now, as investigators seek evidence that Muhammad and Malvo are responsible for those crimes, the travels of the two men and their blue 1990 Chevrolet Caprice through the Washington area become critical to the case.

The pieces of that puzzle have begun to come together, triggered by contributions from people who believe they had encounters with the two men pictured in the photographs released by police.

In a Baltimore Eatery

The night of Oct. 7, as the community of Bowie was reeling over the sniper's latest choice of victim -- a 13-year-old boy, who survived the attack -- witnesses said Muhammad was eating a brownie in a Baltimore Subway store, chatting with other customers and using a laptop computer.

"He was very well mannered," said Marty Ruby, 25, who works at the store in the city's Remington neighborhood.

He said he was from out of town on business and just needed a place to sleep for a bit. He had pulled his Caprice into the parking lot of a nondescript gas station and mini-mart. About an hour later, when workers were locking up, he emerged from the car -- in bare feet -- and apologized.

"We said, 'You're fine, you're okay, hon,' " Ruby recalled. "We just told him to make sure he didn't stay too long because the police will come."

And that's what happened.

Just after midnight, a police officer spotted the Caprice's steamed-up windows and checked on the car. The New Jersey license plate and Muhammad's Washington state driver's license were run through a computer database, but nothing unusual turned up.

In a Blinds Store

On a Saturday -- it may have been Sept. 28, or it may have been Oct. 5 -- Muhammad and Malvo are believed to have entered the Next Day Blinds store at 13505 Connecticut Ave. in Aspen Hill. They asked about purchasing vertical blinds, store officials said.

According to an employee, the younger man, later identified as Malvo, spoke in a Jamaican accent and told the older one, "You don't need these, man."

After a store employee asked them if they wanted a price quote, the men said they were no longer interested and left.

The employee contacted the sniper tip hotline about the encounter after recognizing the two men from pictures shown on television Thursday. Six of the 14 shootings happened in or near Aspen Hill.

Getting a Pizza The crime scene at the Spotsylvania Exxon across the street had been relaxed enough by 8 p.m. Oct. 11 for Pizza Hut driver Joseph Stastny to get through to the Econo Lodge and deliver a pizza.

He said that Muhammad answered the knock on the door of the second-floor room, 11 hours after Kenneth Bridges of Philadelphia had been fatally shot while pumping gas at the Exxon.

Stastny said that the television was tuned to CNN and that Muhammad kept turning toward it.

"He kept looking at the TV," Stastny recalled.

Stastny said he now figures that Malvo was also in the room at the time -- in the bathroom -- because he heard the toilet flush.

He said that Muhammad was gruff, saying only, "You got it?" after handing him the money.

"The older guy paid $16.05, I believe. It was a large pizza," Stastny said. "He gave me a penny tip."

Working Out at the Y

The older man and the younger man he called his son were almost always smiling as they entered the Silver Spring YMCA, where Sharon Douglas works at the front desk.

And they were smiling at Douglas again Thursday, this time in a photograph being broadcast on national television, while a newscaster explained that the men were suspects in the sniper case.

"I thought, 'That looks just like the guy who would come in here with his son,' " she said.

Douglas had seen them at the YMCA about six times, beginning in late August or early September, she said yesterday.

Muhammad "was quite affable," said Steve Kane, a personal trainer.

Muhammad and Malvo had YMCA cards from Washington state with a sticker allowing them to use any YMCA in the country, said Donna Clark, executive director of the Silver Spring YMCA.

In the halls and the locker room of the gym, Muhammad was the talkative one. He was polite and charming. Malvo followed him around and said little.

As they worked out, the sniper attacks were the talk of the gym, as they were across the region. Schools had canceled outdoor recreation. The YMCA in Silver Spring had, too.

At a D.C. Shelter

The Gales School homeless shelter in Northwest Washington does not require people to present identification when they arrive at night.

But a guard who works weekend nights "thought she had seen [Muhammad] there and . . . remembered him because he was so quiet," said Chapman Todd, regional director for Catholic Charities Homeless Services in the District. Another staff member also thought he had seen Muhammad there.

Eating at Outback

The manager of the Aspen Hill Outback Steakhouse believes that Muhammad was alone when he came into the restaurant about 10:30 p.m., shortly before it usually stops serving, and left between 11 and 11:30 p.m. He drank only water -- no alcohol -- with his meal.

Joe Kadow, a spokesman for Outback Steakhouse Inc., said the manager saw the photos of the suspects Wednesday night and contacted authorities.

"She believed that the person in the photo had been in the restaurant and immediately called the police," he said.

Returning to the Gym

The morning after the Outback dinner, about a quarter-mile away, Conrad E. Johnson was shot while standing on the top step of his Ride On bus.

Police were still scouring the area when Muhammad and Malvo walked back into the Silver Spring YMCA, smiling, workers recalled, as they sheepishly explained that they didn't have the $3 guest charge.

After the pair worked out, Kane noticed Muhammad, dripping with sweat after a visit to the sauna and sitting on the locker room bench with his face buried in his hands.

"I asked him if anything was the matter," Kane said. "He said, 'No.' I said, 'Did you have a hard workout?' And he said, 'Yes.' "

The next day, they were back. Again, they didn't have their guest fee. Douglas told them not to worry about it.

Later, Muhammad asked Douglas if there was a television he could watch in private. She said the only television was in the aerobics exercise room. When he saw that it was tuned to a soap opera, he lost interest, she said.

That was the last she saw of him.

The next day, Douglas woke up and saw the picture of Muhammad and Malvo. In it, they are sitting together, their arms draped around each other. And they are smiling.

Stops Along the Way

Shortly before Muhammad and Malvo were caught at an Interstate 70 rest stop early Thursday, witnesses told police that they spotted the men together and separately in three Maryland towns: Frederick, Myersville and Hagerstown.

Federal agents are investigating reports that Muhammad and Malvo stayed at the Hampton Inn Frederick and visited a hotel bar, according to local business owners and managers.

Federal agents also obtained videotape from surveillance cameras at an Exxon gas station in Myersville, according to Elmer Wachter, who runs the station. The Exxon is about half a mile from the I-70 rest stop where Muhammad and Malvo were arrested.

A waitress at a Shoney's restaurant in Hagerstown said she believes she served Muhammad on Oct. 23 -- one day after Johnson was slain on his bus in Aspen Hill. The man ordered the all-you-can-eat breakfast-bar special for $6.99 sometime before 9 p.m.

Pat Slayman, the restaurant's manager, said the waitress recalled that the man asked for directions to Harrisburg before leaving.

"He was by himself," Slayman said.

Staff writer Josh White contributed to this report.

Beginning in late August or September, the sniper suspects started working out at the YMCA in Silver Spring, Sharon Douglas and Steve Kane believe.Steve Kane, of the Silver Spring YMCA, says the man he recognized as John Allen Muhammad was "affable." He had a YMCA card from Washington state.