In the highly competitive security guard business in Northern Virginia, security firms that employ licensed guards are snitching to Virginia officials about other security firms using unlicensed guards.

The victims of the snitching are the unlicensed guards, many of whom did not know they were violating the law by working without a license, according to state officials.

As a result, investigators from the Virginia Department of Professional and Occupational Regulation have brought charges in the past month against 15 unlicensed security guards in Northern Virginia.

"Some of these people (arrested security guards) didn't even know the license program existed. The security firms said to them. 'Here is your gun, here is your uniform - go to work.' The fault, of course, lies with the security firm," said William Stimson, head of security licensing enforcement in Virginia.

Gary E. Morales, 21, a security guard for Clarlmark Security Systems of Alexandria, said he did not know he was violating any law by working at the Ramada Inn at Tysons Corner and earning at $114 a week. Morales was arrested at 8:45 a.m. on a Sunday morning in his parents' red bricl house in McLean. he was charged with working without a license, a misdeamenor punishable by up to a year in jail and a $1,000 fine.

Morales' boss, Mark Seibesi, vice president of Carlmark Security, said that Morales did not know he was working illegally. "It was a common oversigh" that Morales was not properly licensed, Seibels said.

According to state officials, it is the security guards who violate the law by not being licensed, not the security firms that fail to inform their guards about the law's existence.

The security licensing law, which went into effect in November 1976 and was passed by the state legislature despite intense lobbying against the measure by security firms in Virginia, requires, among other things, that guards working for contract security firms take a state-approved training couruse within 120 days after going to work.

The state obtained warrants for the arrest of 15 guards in Northern Viriginia because of complaints from security firms that are complying with the law, according to Nicholas Beltrante, executive director of the private security section of the Virginia Department of professional and occupational regulation.

"The security firms complained that if they hasto license their guards, so should their competitors," Beltrante said.

Morales, according to his lawyer, Dale Sanders of Alexandria, is caught between the competitive jealousies of security firms and faces punishment under a law that deals more severely with unknowing violators than with the security companies that fail to inform their guards about the law.

Beltrante said the state is planing soon to take adminstrative action against security firms that permit their guards to work without licenses. He said that while the state cannot criminally prosecute the firms for empolying unlicensed guards, it can suspend or revoke their operating licenses.

The licensing law, according to Beltrante, is widely ignored across the state. He said his department estimates about half of the 10,000 security guards in the state are not licensed.

Prior to the arrests last month in Northern Virginia, Stimson said the state had been only warning security firms to license their guards. Pressure from complaining competitors forced the arrests Stimson said.

Smaller local security firms have filed most of the complaints against national security firms operating in Virginia, according to Beltrante. He said the state will not release names of the security firms charged until administrative hearings begin, probably within the month.