MARIETTA, Ga. -- A former employee apparently chose his targets at random in a shooting rampage at an Atlanta-area truck rental business that left two men dead and three in critical condition, the company's president said Wednesday.

Jessie James Warren, 60, was arrested in his pickup truck shortly after the Tuesday attack. He is charged with two counts of murder and five counts of aggravated assault.

Police said a man dressed in camouflage stormed the Penske Truck Rental facility in Kennesaw, about 25 miles northwest of Atlanta, in the nation's second fatal workplace shooting spree this month.

Killed were 59-year-old Van Springer of Woodstock and Jaider Phillipe Marvlanda, 43, of Lawrenceville, said Cobb County Police Officer Joe Hernandez.

Four of the victims were Penske employees while Marvlanda was a truck driver for a local food distributor that is a Penske customer, said Brian Hard, the president of Penske Truck Leasing.

"It appears to have been random, to come in and shoot one of our customers who couldn't possibly have been involved in any grievance," Hard said.

Warren, who was denied bond in a brief court hearing at the Cobb County Jail, worked at Penske as a technician from June 2005 until July 2009, said Hard. He would not say why Warren left the company, but the widow of one of the victims said Warren had been laid off.

Police have not disclosed a motive, although Hernandez described Warren as a "disgruntled ex-employee." Hard also said he would not provide any more details of Warren's employment pending the police investigation.

"We are all still trying to understand what happened and we are fully cooperating with law enforcement officials," said Hard. "It is important that we let law enforcement do their job without interference."

Barbara Springer, wife of Van Springer, said that Warren had been laid off recently and that "he had some issues," though she would not elaborate. She said her family is trying to pull together but they are "not (doing) very good."

It was the second fatal U.S. workplace shooting this month. Timothy Hendron, an employee at an ABB Inc. electrical plant in St. Louis, is accused of shooting hundreds of rounds of ammunition through the sprawling plant as about 50 workers sought refuge. Authorities say he killed three men and injured five others before killing himself.

In the Georgia case, about two dozen employees were working at the Penske office, consists of a couple of large buildings with bay doors, Penske spokesman Randy Ryerson said.

The gunman first confronted someone in the parking lot before moving to the truck bay area, shooting victims along the way, said Hernandez. He did not try to enter the building's second floor, which houses a small administration office.

A man who witnessed the arrest said the suspect looked "out of his mind" and "all drugged up."

"The cops walked up on both sides of the truck, he opened the door and they threw him on the ground. He pretty much just gave up," Michael Robertson told The Associated Press.

Lights were on but no one appeared to be home Tuesday night at an address listed for Warren in Temple, a rundown house with an overgrown lawn on a rural stretch of two-lane highway. No one answered the door but a dog could be heard barking. A few neighbors contacted by telephone said they didn't know Warren.