"An entire city desperately wants to know why do bad things happen to good people, why no one, including our innocent children, is immune from the evil of violence," Mayor Bill Campbell said during a memorial service at the Peachtree Road United Methodist Church.
Traffic slowed and business stopped in much of Atlanta to mark a moment of silence in honor of the victims.
As Mark Barton's victims were were being mourned, more information was coming to light about the killer's financial life.
In interviews with some of the people who day-traded with Mark Barton, 60 Minutes II learned that Barton, nicknamed "The Rocket" by fellow traders, was a particularly aggressive trader.
According to Harvey Houtkin, the owner of All Tech Investments, where Barton traded, there was one day when Barton made a $106,000 profit. Even by the inflated standards of day trading, this is a lot of money, Houtkin says. There were days, he says, when Barton would stake up to a quarter of a million dollars.
But this daring behavior led to big losses, too. A year after he opened an account at All-Tech, the company forced him to close his account. He had run out of money, Houtkin says.
A few weeks later, Barton opened an account with another day trading firm, Momentum Securities, across the street from All-Tech. Less than two months later, he had lost $105,000 there. His account there was closed July 27.
Later that evening, Barton murdered his wife. That Wednesday morning, he attempted to reopen his Momentum account with a $50,000 check. The office manager refused to accept it. That night, he bludgeoned his two children to death.
Buried on Tuesday were two of the day traders killed Friday, Edward Quinn and Joe Dessert. They were among the nine people killed when Barton opened fire inside two Atlanta brokerages.
He started by killing his wife Leigh Ann at their home. That led to a string of murders that would become Georgia's worst mass killing this century.
Barton's two young children were buried Monday in Lithia Springs: 11-year-old Matthew and 7-year-old Mychelle.