The first two people Thornton, 34, killed at Hartford Distributors were escorting him out of a meeting where he had resigned after being shown a video of himself stealing beer. Manchester police Lt. Christopher Davis said Wednesday.
Busted, he didn't put up a fight, company officials said. He quietly signed a letter of resignation and was headed for the door.
As he was being escorted out, Thornton asked for a glass of water and went into the kitchen. It was there were, police said, he had a lunchbox containing at least one of the two 9 mm handguns police would later find on him.
By the end of his rampage on Tuesday morning, Thornton had killed eight people, injured two, then turned the gun on himself at Hartford Distributors.
Police are still investigating, but offered chilling details about what happened in the building. Thornton went through the whole building, shooting some and passing by others. One person he passed by was a disabled woman who told police she felt lucky to be alive.
Union and company officials said they would not have anticipated this from someone with no history of complaints or disciplinary problems.
NBCConnecticut confirmed that at least five employees tried to warn their fellow workers and/or stop Thornton during his murderous rampage -- including a 77-year-old man who tried to run him over with a golf cart.
That man in the car, Jerome Rosenstein, was left fighting for his life at hospital.
After shooting his co-workers, Thornton hid as police moved in. He called his mother, who tried for 10 minutes to talk him out of killing himself, his uncle Will Holliday told NBC Connecticut.
Relatives say that Thornton, 34, cracked after suffering racial harassment in a company where he said he was singled out for being black in a predominantly white work force.
"He said, 'I killed the five racists that was there that was bothering me,"' Holliday said. "He said, 'The cops are going to come in so I am going to take care of myself."'
Thornton had said he found a picture of a noose and a racial epithet written on a bathroom wall, Hannah said. Her daughter told her that Thornton's supervisors said they would talk to his co-workers.
Brett Hollander, whose family owns the distributor, denied any racial bias. And a union official said Thornton had not filed a complaint of racism with the union or any government agency.
"I can assure you, there has never been any racial discrimination at our company," Hollander said.
"This is a disgruntled employee who shot a bunch of people," Christopher Roos, a Teamsters official, said.
Authorities recovered two 9 mm handguns from the warehouse and a shotgun from Thornton's car. He says the guns were registered legally, and the shotgun apparently wasn't used.