The terror began on the evening of Oct. 2, when James D. Martin, a 55-year-old program analyst for the National Oceanic and Atmospheric Administration, was gunned down in the parking lot of a Shoppers Food Warehouse in Wheaton.

The next morning, James "Sonny" Buchanan, 39, was mowing the lawn at the Fitzgerald Auto Mall in Bethesda. Premkumar Walekar, 54, was filling his taxi at a Mobil station in Aspen Hill. Sarah Ramos, 34, was sitting on a bench outside Leisure World. Lori Ann Lewis-Rivera, 25, was vacuuming her minivan at a Shell station in Kensington.

In little more than two hours, all were dead.

Vickie Snider was at an exercise class in Rockville when word of a shooting came. Class was canceled; the participants were told to get into their cars and go home.

Snider watched the news throughout the day. She had plans to catch up with her brother later. It wasn't until that evening, when the police detective came to her door with Buchanan's driver's license, that she learned he had been killed.

"You just go numb," she remembered last week. "It's like your brain can't handle it. You just want to say, 'No, it's a mistake.'

"Then I had to tell my parents."

With much of the Maryland State Police leadership away at a conference, Maj. Vernon Herron was acting chief of field operations statewide when the shootings began. He says the case was unlike any in the nation's history.

"Of course, we were all dumbfounded," said Vernon, now a senior policy analyst at the University of Maryland Center for Health and Homeland Security. "There was no ransom demand, there were no statements, nobody was taking responsibility for the attacks. ... Normally when somebody does something like this, they want to take credit."

The first communication came on Oct. 7. Iran Brown, 13, was arriving at Benjamin Tasker Middle School in Bowie when he was shot in the torso.

This time, police found a message at the scene: The death card from the tarot deck, inscribed with a note. "For you Mr. Police/Code: 'Call me God'/'Do not release to the press.'"

LaRuffa, who had spent 10 days in the hospital after the September attack, followed the news from home. His shooting remained unsolved; while friends suggested it might have been the work of the sniper terrorizing the area, he didn't think so.

His attacker had walked up to his car, shot him several times at close range and stolen his laptop computer and $3,500 in cash from the restaurant. Whoever was killing people was using a single bullet fired from a distance.

In fact, investigators would learn, Muhammad and Malvo had staked out LaRuffa at his Margellina Restaurant before the attack. They were using his money to finance their killing rampage. From Oct. 9 through 14, they killed three more people, all in Virginia.

Snider, grieving for her brother, winced at every new report.

"The whole thing was so surreal and so sad, and for them to take so many lives in such senseless ways," she said. "They were all hardworking people just going about their daily lives.

"Just watching other people die as the week went on, that was very difficult, to know that other families were going through what we were going through."

Duncan, the former county executive, says he had a responsibility to present a face of calm to the community as he appeared at public meetings, news conferences and funerals.

At the same time, he said, "When I went home early in the morning, I didn't dawdle. I scurried into my house. You're on TV a lot, and you know they're watching because of their communications. You just assume that you've become a bigger target."

He speaks with pride about the courage of the community, and cites an example.