Porter remembers a blur of action as she ran outside.

The driver jumped out. Porter heard three shots, then witnessed a scene that brings tears to her eyes.

"The driver ... had a gun in his hand, and the guy who was chasing him shot him," Porter said. "Then he hit his knees and started crying, because he turned around and saw the lady in the car was dead. I heard him say, 'Oh God.' "

The crime was as random as one could imagine.

A stranger carjacks a woman in broad daylight. There's a crash. The woman dies. Her abductor is shot and killed — not by police but by an armed passer-by who gave chase in his truck.

That man, Shawn T. Roberts, has emerged as a hero for trying to help 30-year-old Kimberly Boyd and for saving other lives that police say might have been taken had the carjacker escaped.

"Scores of people were coming up to him and thanking him for what he did," said Scott Cannon, a friend of the Boyds who attended Kimberly's funeral Friday.

Roberts was among those who came to pay respects.

"He wanted everyone to know she didn't go down without a fight," said Brandon Henderson, a friend of the Boyds' who spoke to Roberts during the service.

"He said, 'Just so you all know, Kim was whipping his ass on the side of the road before he grabbed her and threw her in the car.'"

Although police say Roberts acted courageously, such acts have not always met with official approval. Cobb County District Attorney Pat Head and the grand jury will have the final word on Roberts' legal fate.

But this much is certain: In a matter of moments, in an act of violence and happenstance, three disparate lives became intertwined on that highway last Monday morning.

Unlikely carjack site

Kimberly Boyd owned a truck rental company in Acworth, a Cobb County community where the Appalachian Mountains yield to the granite Piedmont.

Boyd's business is in a strip mall, with a Big Lots, a Waffle House and several other businesses — one of the last places you might notice someone lurking.

But Brian O'Neil Clark, a 25-year-old felon who had been released from prison three months earlier, was there.

That morning, Boyd left her home in Paulding County before 8 a.m. She dropped her 5-year-old son, Connor, at school and drove to her office. Police believe she was abducted by Clark in the parking lot.

At 9:25 that morning, Boyd used her ATM card to withdraw money outside a Wachovia bank about 5 miles away.

"We speculate that she went to that area hoping someone would see her and become suspicious," said Kevin Flynn, a homicide lieutenant with the Cobb County Police Department. "This indicates she was cool-headed and doing everything she could to survive because there were other banks closer to where she was abducted."

Roberts first saw Boyd and Clark about 1 1/2 miles south of the bank. Clark hit Boyd with his fist and a gun as the two struggled along Cobb Parkway, just past a bridge over Allatoona Reservoir.

At some point, Clark shot Boyd.

He then shoved her into the back seat of the SUV and sped away. As Boyd's SUV careened down Cobb Parkway, Roberts gave chase.

Then came the crash.

At Lake Acworth Drive, about a half-mile from where Roberts saw Boyd and Clark fighting, a cement truck moving northbound on Cobb Parkway crashed into the SUV as Clark tried to make a sharp left turn off the highway.

The accident's impact killed Boyd.

Clark emerged from the crumpled SUV and started running toward a gas station.

As Roberts approached, Clark raised his gun.

That's when Porter heard the shots from outside her office at Atlanta Tile Specialists.

Clark fell in a heap, dead.

Boyd, still inside her SUV, was already gone.

At the Cobb County 911 center, the call boards lit up "like a Christmas tree," Flynn said.

The first caller told an operator there had been a bad accident and someone had been shot.

Family came first

Kimberly Boyd put her children and her husband above everything else, including her business.

She used to take Connor and her 2-year-old daughter, Chloe, to work with her so she could spend time with them throughout the day.

"There were toys all over the floor of her store," said Janeice Confer, who manages a truck rental franchise nearby. "She was a very devoted mother."

She spent two years at the University of Georgia in the mid-1990s. Mike Boyd, eight years her senior, went to college in Tennessee.

"The only thing I ever heard those two argue about was Georgia-Tennessee," Henderson, a friend of the Boyds', said with a chuckle. "Kim would call me for stats —'Quick, how many points did Georgia score off Tennessee last year?' "

The couple recently got custody of Mike's 13-year-old son, Nathan, from a previous marriage, and Kimberly told her friends she didn't think she could raise all three children while running a business.

So she was looking for someone to buy her out.

But Monday, she had a customer coming in at 8:30 a.m. She had to make sure the truck was ready to be picked up.

Chloe had a cold, so Mike stayed home.

Kids first, work second.

"It was a family that had everything together," said Scott Cannon, who coached Nathan's baseball team in Woodstock.

The day after his mother was abducted and killed, Connor went to his room and drew a picture. He asked his dad if his mother would ever see it.

"Yes," Michael Boyd told his son.

"She'll love the picture, and she'll be with you forever."

The drawing was in Kimberly's casket Friday when she was buried.

It's a picture of a teddy bear, with the words "I LOVE YOU MOMMY."

Hailed as a hero

Shawn T. Roberts lives in the sprawling Bentwater subdivision in Paulding County. It's only about a mile from the Boyds' home, but it doesn't appear as if the two had ever met.

Roberts, 31, owns a home theater and burglar alarm company and carried a licensed pistol.

Before he stopped speaking publicly about the incident, he said he had no choice, that had he not acted, more people could have been harmed.

And that's how his actions are being seen, in metro Atlanta and across the country.

Web sites and blogs are filled with postings crediting Roberts for his fast thinking and for trying to save lives.

"This guy probably saved another 25+ victims ..." a poster with the screen name "Taurus" said on a message board at www.packing.org, a Web site for advocates of concealed-carry laws. "Shawn Roberts is a hero in my book."

Police and community leaders seem to agree.

"You drive by a man beating a woman on the side of the road, you have to do something," said Deanne Bonner, president of the Cobb County chapter of the NAACP.

Said Flynn, the homicide lieutenant: "I want to stress that ... we have found no violations of Georgia law. That being said, the district attorney will make the final decision."

Although Roberts knew nothing about Clark's background at the time of the shooting, police seem to think there's a good chance others might have been hurt had Roberts done nothing.

In April 2002, Clark was arrested in Illinois and brought back to Georgia to face child molestation, statutory rape and burglary charges in Cobb County, where he received an 18-month sentence, jail records show.

In May 2004, Clark was charged in Cherokee County for first-degree forgery. He served a year in state prison and was released June 13.

Police also suspect Clark is responsible for a rape, carjacking and robbery in Acworth on Sept. 6.

In that case, police believe Clark beat and raped a woman, then forced her to drive to a nearby bank so he could withdraw money from the bank's ATM.

During that attack, Clark stole a gun from the woman's home, police said.

That gun was finally found Monday — near Clark's body after he was shot.