Authorities believe a fugitive Georgia professor on the run since allegedly gunning down his wife and two others intentionally put his Jeep into drive and let it plummet into a ravine near his home.

They also theorize that George Zinkhan, 57, is still in the Atlanta area — where he lives and teaches business courses at the University of Georgia — and that the rampage may have been sparked by a fight with his wife, who reportedly was planning to leave him.

"We don't believe he drove it off, 'cause it's in drive," one officer told reporters of the crashed Jeep, according to MyFOXAtlanta.com. "Looks like he put it in drive and maybe kind of pushed it off the edge."

Police hadn't previously revealed a motive, but FBI agent Greg Jones said Friday that interviews with friends and family indicate the shooting likely stemmed from a domestic dispute between Zinkhan and his wife, 47-year-old attorney Marie Bruce.

Authorities have some indication she was preparing to file for divorce, he said.

Detectives swarmed the heavily wooded area where Zinkhan's wrecked red Jeep was discovered Friday, but turned up no sign of the fugitive professor. Some officers in pickup trucks drove down dirt roads and helicopters searched from above.

He has been missing since last Saturday, when he allegedly fled the scene of the triple shooting murders of his wife and two other men at a community theater where the victims were members.

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Zinkhan was last seen driving away in the Jeep after dropping his children off with a neighbor. The children were in the car during the shootings but weren't hurt.

The Jeep was found overnight "well off the beaten path" in a ravine in Bogart, a rural community about 10 miles west of Athens, where Zinkhan lived and taught marketing at the University of Georgia's Terry College of Business, according to Jones.

A signal from one of Zinkhan's cell phones helped led authorities to the Jeep, Jones said, but he wouldn't elaborate. The Jeep likely had been in the ravine since shortly after the shooting, he said.

Zinkhan is accused of killing Bruce and two members of her community theater group, Ben Teague, 63, and Tom Tanner, 40, in front of a theater in Athens, Ga.

Authorities across the nation and in Europe have been looking for Zinkhan since the April 25 shootings.

Authorities were searching a 200-acre area near the ravine. A nearby elementary school was locked down as a precaution.

Jones said authorities were piecing together some leads from evidence in the Jeep, but declined to give any details.

Zinkhan is an avid hiker who has spent time on the Appalachian Trail.

In 2003, Zinkhan wrote a short poem called "Appalachian Trail, Southern Terminus" for the American Marketing Association's Web site. The 2,178-mile trail's southern terminus is at Georgia's Springer Mountain, about 50 miles northwest of Athens.

Authorities said earlier this week that Zinkhan had a flight to Amsterdam booked for Saturday. Zinkhan has taught part-time at the Vrije Universiteit (Free University) in the Netherlands since April 2007.

Zinkhan's brother has said relatives have been working to help Athens-Clarke County police and the FBI find him.

The University of Georgia is warning students to be cautious until he's found.

Before joining the faculty at the University of Georgia, Zinkhan held academic positions at the universities of Houston and Pittsburgh.

He has a doctorate from the University of Michigan and graduated from Swarthmore College in Pennsylvania in 1974.

The shooting victims were members of Town & Gown Players, which was staging a performance of "Sherlock Holmes: The Final Adventure" at the theater.

Two others were hurt by bullet fragments.

Zinkhan's wife, had been serving as Town & Gown's president after years of volunteering with the group.

Tanner was a Clemson University economist who taught at the Strom Thurmond Institute of Government and Public Affairs in Clemson, S.C.

Teague was one of Town & Gown's longest-serving volunteers and was married to a University of Georgia English professor.

Click here for more on this story from MyFOXAtlanta.com.

The Associated Press contributed to this report.