A man who has worked as a corrections officer at the District of Columbia's Lorton prison complex since August has been arrested by Alexandria police on robbery and firearm violation indictments returned almost five years ago.

Leonard S. Woolfolk, 32, who passed a background security check before he went to work at the facility in southern Fairfax County Aug. 20, had been indicted in February 1980, according to Alexandria Circuit Court records. A bench warrant was issued for his arrest at the time, and Alexandria police said yesterday there was "some confusion" as to why he was not apprehended until last Friday.

Alexandria police spokeswoman Lucy Crockett said Woolfolk's name had been entered into the FBI's National Crime Information Center computer as wanted on the armed robbery and the firearm charges.

D.C. corrections spokesman Leroy Anderson said the FBI routinely investigates the background of all guard applicants and he could not explain why that investigation did not unearth the fact that Woolfolk was wanted by Alexandria authorities.

An FBI spokesman said he was not sure why the agency's check did not disclose the existence of the indictment. He said the spokesman for FBI's Washington field office, which conducts most such background checks, was unavailable yesterday for comment.

The charges against Woolfolk came to light this week as the result of an inquiry to the Alexandria authorities by the D.C. fire department, which routinely makes background checks on job applicants with Washington area police departments. Woolfolk had applied for a D.C. firefighter job last month.

Dorothy Weber, Alexandria's public safety records coordinator, said a member of her staff checked the names of the job applicants listed by the D.C. department against outstanding warrants on file in Alexandria and discovered the warrant for Woolfolk's arrest.

Weber said Lorton prison officials have never asked Alexandria police to investigate guard applicants. Anderson confirmed that local police departments are not contacted in employe investigations.

Woolfolk was released Friday under $1,000 personal bond and placed on a five-day administrative leave from his guard's job pending an investigation by the prison into the charges against him, according to Anderson.

The robbery with which Woolfolk is charged occurred at the Park & Shop parking lot at 105 N. Lee St., Alexandria, on Dec. 27, 1979. Parking lot attendant Chawla K. Wantu was robbed, struck on the head, and shot at by a man Wantu identified as Woolfolk, police records show.