Fairfax County Police Chief Carroll D. Buracker had gone home to Kings Park West for lunch Wednesday when the dispatcher alerted him to the hostage incident at Lake Braddock Secondary School. Jumping into his unmarked cruiser, Buracker drove the short way to the scene and was the the third officer to arrive.

He stayed there until 10 a.m. yesterday, acting as a liaison between the police and the school system, keeping county officials abreast of developments and making statements to the news media.

Such is the style that Buracker has brought to a department known to some for the wall it has drawn between its chief and the public. Among reporters, the county has been known for its strict limits on access to members of the force. Traditionally, all information has been disseminated through a public information officer.

The 40-year-old Buracker, in contrast to Richard A. King, his predecessor, has been highly visible since he was named chief of the 720-member department in August 1981. Last month, after a Reston woman alleged she had injured her eye with a bottle of Visine A.C. eye cleanser that had been tampered with, Buracker summoned a late night press conference to express his doubt over the claim.

To some of his colleagues it was not surprising that the chief was among the first to a scene. "I was there, but the men did the work," he said yesterday. "I like to stay out of their way, but I like to be close by too."

A country boy who grew up near Luray, Va., Buracker became an Army military policeman and later joined the Harrisonburg, Va., police force. He came to Fairfax in 1966 as a field officer and rose through the ranks.