(CNN) -- Public safety officials in Texas Thursday released a video of a man throwing a Molotov cocktail at the governor's mansion in 2008, hoping it and a suspect sketch will lead to his identification.
The Department of Public Safety and its Texas Rangers division are offering a $50,000 reward for information that leads to the arrest and conviction of the person or persons responsible for the arson.
"We're quite confident someone knows who this suspect is," Steven McCraw, director of public safety, said at a press conference.
Authorities, who say the thrower is the same person shown in another video at a rear gate outside the mansion, hope a relative or acquaintance will recognize his appearance, gait or run.
They also released video of a white Jeep Cherokee whose occupants were taking photos of the mansion four days before the June 8, 2008, fire in Austin.
The vehicle owner and two other occupants in the Jeep are called "persons of interest" in the case.
Investigators said they have established a direct link between the three and an Austin-based anarchist group linked to a planned attack on the Republican National Convention in Minneapolis in September 2008, which also involved Molotov cocktails.
The person throwing the fire device at the mansion is not believed to be one of the three people in the vehicle, officials said.
"We need somebody's help in linking these people together, said Ranger Capt. Antonio Leal.
Officials studied 1,900 hours of video taken by 11 cameras at or near the house that has served as the official residence of Texas governors and their families since 1856. Gov. Rick Perry was not living in the mansion at the time of the fire because it was undergoing repairs.
According to an accompanying statement, the three persons of interest have denied involvement in the fire.
"One passenger initially denied having been in the vehicle, but later admitted to having been in the vehicle and taking photographs after failing a polygraph examination," according to the statement.
At least one of the persons of interest has been placed in the downtown area the morning of the mansion fire, officials said.
White authorities call the three persons of interest and know their identifies, McGraw said he will not identify the Jeep occupants until the department has enough evidence to prosecute them.
The Texas fire and the planned attack in Minneapolis involved Molotov cocktails, he said.
"We don't believe in coincidences," McGraw told reporters.