Another Ohio realtor was found murdered on the other side of the state a few days earlier.
The Portage County Sheriff's office issued a murder warrant for Grigelaitis last week.
Court records indicate Grigelaitis was charged with three counts of aggravated assault with a firearm in May 2009.
Grigelaitis was also involved in a real estate lawsuit in Ohio in 2008, though it isn't clear if or how VonStein was involved.
A Wilton Manors police spokesperson said Grigelaitis should be considered "armed and extremely dangerous."
Police say Grigelaitis is about five-foot-ten, 200 pounds, with short salt-and-pepper hair and blue eyes.
He was last seen driving a 2007 Ford F-350 Super Duty Crew Cab Dually pickup truck with the Florida license plate number 661-XYL.
He suspects the murder was part of a plan to rob VonStein. (The victim's wallet and cell phone were both missing when he was found.)
"There are serious dangers to this business," said the realtor friend of VonStein's, who worked with him for more than ten years but doesn't want his name published. "We're going out to meet strangers by ourselves. There are precautions you can take -- and Andy did -- but if someone means you harm, to a certain extent, you're at their mercy."
UPDATE: Grigelaitis was arrested at a rest stop in North Carolina by the U.S. Marshals Service. He was armed with a handgun but taken without incident. He waived an extradition hearing and was taken back to Ohio and booked into the Portage County jail. He's being held on a $2 million bond. According to the Record-Courier, a newspaper in Ohio: "Wearing an orange and white jail uniform, Grigelaitis greeted [Municipal Judge Mark] Fankhauser with 'afternoon, judge' and responded to the judge's questions with 'yes, sir' during the brief hearing."
UPDATE II: Grigelaitis was indicted in Portage County Municipal Court this morning on three counts of aggravated murder.