Fairfax County school officials who want to implement criminal records checks on thousands of job seekers and current employes may face legal, logistical and financial impediments to their plan, school and law enforcement officials said yesterday.

School Superintendent Robert R. Spillane said in a news conference Monday that he wanted to perform the criminal records checks on the system's applicants and 13,000 full-time employes.

Spillane's announcement came after a former county school psychologist was charged with two counts of sexual battery involving young boys. The psychologist, Arthur S. Pomerantz, 46, resigned from his job in 1984, three years after police began to investigate his alleged activities with the youngsters.

Pomerantz's attorney, Mark E. Sharp, has said his client denies the charges and intends to plead not guilty in proceedings in Fairfax County Juvenile and Domestic Relations Court.

Spillane could not be reached yesterday for further comment on his proposed measures.

But school personnel director R. Warren Eisenhower acknowledged that school officials do not know who would conduct the records checks, what the cost of such checks would be and what information they could legally retrieve.

"These are all questions we're trying to find the answers to," said Eisenhower.

Monday's announcement on the records checks seemed aimed at allaying the fears of parents and school officials that some school employes might have criminal records that school officials are not aware of.

But school officials conceded yesterday that even if checks of criminal records had been in place, Pomerantz, who had no criminal history, would not have been screened from the school system's payroll.

Moreover, law enforcement officials said yesterday, the school system probably would have access only to records of criminal convictions -- and perhaps only those within Virginia. Police records of investigations or arrests without convictions, as well as criminal records from other states, are not readily available, the officials said.

"I would not categorize it as an easy thing to do," said David Hathcock, a spokesman for the state attorney general's office, referring to Spillane's wish to conduct thorough criminal records checks on school employes.

School personnel director Eisenhower said that because many employes are not Virginia natives, Fairfax would have to perform the records checks on a nationwide basis.

Eisenhower said he had not computed the cost to the school system of such a national check, and that school officials had not done a cost-benefit analysis on the plan. He did say, however, that spot checks state police perform for the county school system cost $5 each.

Under any program the school system might adopt, applicants as well as current employes would have to give their consent for the checks to be performed, officials said.

Until about 10 years ago, the county schools took fingerprints of all job applicants and submitted the prints to the FBI for a criminal record check. The FBI ended the service in the mid-1970s, according to Eisenhower.

Eisenhower said he does not know how many applicants the state police check at the request of the school system.

Civil liberties groups have raised objections to any kind of background checks that go beyond information concerning criminal convictions.

Barry W. Linn, legal counsel for the American Civil Liberties Union, said his organization would oppose any checks that included information on arrests and investigations.

"For that undistilled information to be passed on to everyone that might be considering hiring such a person is a very serious abridgment of due process of law," said Linn.