Officials at the District of Columbia's Lorton Prison complex said yesterday they have tightened the application procedure for corrections officers after discovering that they had hired a guard who had been wanted on criminal charges for more than four years by Alexandria police.

Lorton officials said they now will send a written inquiry on job applicants to the area police department nearest the applicant's residence.

In addition, James K. Slade, chief of Lorton's applicant background identification division, said that he will request greater use of the FBI's National Crime Information Center computer. It contains a listing of outstanding criminal warrants.

Until now, Slade said the prison's hiring procedure included a fingerprint check with the FBI and inquiries to D.C., Virginia and Maryland state police.

"We've covered all the cracks this time," said Slade. "No one will slip through again."

D.C. corrections officials were embarrassed when Leonard S. Woolfolk, 32, a Lorton corrections officer, was arrested Friday by Alexandria police on 1980 robbery and firearm violation charges. He had worked at Lorton since Aug. 20.

The 1980 warrant for Woolfolk's arrest came to light last week as the result of an inquiry to the Alexandria police by the D.C. Fire Department. The fire department routinely sends background inquiries on job applicants to area police departments and did so when Woolfolk applied for a D.C. firefighting job last month.

When Alexandria police discovered his whereabouts, they issued a warrant for his arrest. Alexandria police spokeswoman Lucy Crockett said Lorton had not inquired if Woolfolk was wanted before he was hired and that his name had been listed in the NCIC computer since February 1980.

Slade said the prison has access to the computer, but had not requested that a check be made of outstanding warrants. "As a result of this incident," he said, he will request that the prison make those checks in the future.