All five of them were doing the most ordinary things before a gunman ended their lives, one at a time, over 16 hours.

James Martin was in a grocery store parking lot on his way home from work.

Sonny Buchanan was mowing the lawn outside a car dealership.

Prenkumar Walekar was pumping gas into his taxicab.

Sarah Ramos was sitting on a bench, waiting for her boss.

Lori Ann Lewis-Rivera was cleaning her minivan.

Last night, the police effort by dozens of local agencies had identified few threads to tie the victims of a proficient gunman whose targets crossed lines of culture and class.

One was black, one was Hispanic, one was Indian, two were white. Their ages ranged from 25 to 55. One was on foot, another tending to a well-kept vehicle.

How the killer chose his targets is a mystery. All Montgomery County Police Capt. Nancy Demme could say was that the victims "are across the board in gender and ethnic backgrounds."

James D. Martin

James D. Martin was heading home about 6 p.m. Wednesday to the Stonegate neighborhood in Silver Spring when he stopped at the Shoppers Food Warehouse on Randolph Road in Wheaton. Within moments, Martin, 55, had been shot, the 21st person killed in Montgomery County this year.

Last night, friends and family members clustered outside the home he shared with his wife and young son, a two-story house with light-green siding and blue shutters in the 15200 block of Centergate Drive near Colesville. Neighbor Ruth Dalton remembered Martin as the kind of neighbor who would be missed - especially at Halloween.

"He was extraordinarily friendly from the time he moved in," she said. When trick-or-treaters called, he was known for "making a big fuss over them."

'Sonny' Buchanan

James L. Buchanan Jr., 39, had no children of his own.

But for nearly a decade, Sonny, as he was known, served on the regional board of the Boys and Girls of Greater Washington. He volunteered with the county's Crime Solvers hot line. He doted on his two nieces and two nephews and a great-niece who turns 1 next week.

"He took a great interest in the kids of this county," said Tim Sheehan, executive vice president of the Boy and Girls Club of Greater Washington.

A classmate from Gaithersburg High School, Janice Kidwell, said those priorities never wavered.

"Family meant the world to him and he had a real commitment to community," she said.

After graduating from Gaithersburg High in 1977, Buchanan earned a business degree from the University of Maryland.

He preferred working for himself, running a landscaping business out of the home on Grandin Avenue in Rockville that he shared until last spring with his mother, Alice, and the eldest of his two sisters, Debbie Cox. The lawn outside the one-story cream-colored house with a green front door still bears signs of his labors.

This summer, he moved to Grayson County, Va., to live with his father.

James L. "Buck" Buchanan Sr. is a retired Montgomery County police officer who runs a tree farm near Abingdon.

Father and son spent the warm months building a new house near the farm, said Sonny's uncle Coy Wilcox.

"He thought the world of his boy. They were very close," Wilcox said. "We're tore up about it."

Although he'd moved away, Buchanan still honored a decade-old contract he had to mow the lawn outside Fitzgerald Automotive on Rockville Pike.

He was there at 7:40 a.m. yesterday when a gunshot caught him mowing grass.

He died en route to Suburban Hospital as his friend Rob Smith, the dealership's service manager, sobbed beside him.

Victoria Buchanan Snider, wept, too, as she recalled a brother with soulful, dark eyes and a playful smile. He was her best friend, she said.

"He was just unbelievable," said friend Rose Wilkes. "If you needed him, no matter what he would always be there."

Premkumar Walekar

Premkumar Walekar, who turned 54 last month, was the third man to die.

A native of India who lived off Georgia Avenue in Olney, Walekar drove a brown independent cab and often stopped at the Mobile station in Aspen Hill on his way into work.

Mechanic Warren Shifflet saw him arrive yesterday shortly before 8:15 a.m.

"I saw him standing right there pumping gas," Shifflet said, pointing out the pump.

But then another mechanic, Alex Millhouse, realized the cabbie had clutched his left side and slumped against a nearby van as his blood pooled onto the blacktop.

At that moment, the van's female driver cried out: "He's been shot, he's been shot."

Then she sprang into action, administering cardiopulmonary resuscitation to Walekar as he struggled to breathe, but nothing could save him.

Standing outside Walekar's house in Olney last night, family friend Jesmond Marshall smoked a cigarette and spoke of regret.

"He didn't deserve this," Marshall said. "He worked all his life for his family, and now he doesn't even get to see his grandkids."

Marshall said Walekar was a hard-working family man who emigrated from India almost 30 years ago. After marrying, he and his wife, Margaret, bought the two-story brick house in the 18800 block of Rolling Acres Way, in a suburban postcard neighborhood of leafy trees and tidy lawns.

It is there they raised a 23-year-old son who works as a computer programmer and a 24-year-old daughter who attends the University of Maryland, both of whom live at home.

Last night, their street was clogged with nearly two dozen cars.

"We're Indian," said Marshall. "We all come together at a time like this."

Sarah Ramos

Strangers came together last night to memorialize Sarah Ramos, a cleaning lady who lived in the 11400 block of Lockwood Drive in the Burnt Hills area of Silver Spring.

Ramos, 34, was in her usual spot yesterday at 8:37 a.m., sitting on a gray metal bench outside the Leisure World post office while she waited for a ride to work.

Late yesterday, the bench began to overflow with flowers, some simple, some fabulous.

Hanging from a glittery blue-dyed daisy bouquet with a cross painted like the American flag, a card read: "God Bless You."

Lori Ann Lewis-Rivera

Witnesses who saw Lori Ann Lewis-Rivera, 25, fall to the ground first thought she'd suffered a heart attack.

She was vacuuming her maroon Dodge Caravan at a Shell gas station in Kensington when John Mistry heard a noise like a backfire and realized she was on the ground.

A neighbor, Rosa Malone, 60, described Rivera as a nice, kind person with whom she often exchanged greetings on her way into their three-story brick apartment complex in the 1500 block of Hampshire West Court.

"She was a very soft-spoken and kind person. She was a good neighbor. She was like a family member.

"I'm just blown away," Malone said. "I'm just blown away."

Another neighbor, Janaina Rocha, 29, said Rivera's preschool-age daughter was a regular at her four kids' birthday pool parties. Lewis-Rivera and her husband was looking forward to their lives and buying a house. Rivera was very reserved and didn't discuss much about her personal life, Rocha said. She had lived at the apartment complex for about three years.

"She was a very sweet person," Rocha said. "I'm terrified. There are a lot of bad things happening."

Sun staff writer Del Quentin Wilber and research assistant Paul McCardell contributed to this article.