A technical glitch in the LX4000 polygraph machine that has produced errors in its sweat measurements arose in one of the three machines used by the Beaufort County Sheriff's Office between 2002 and 2010, according to the county's attorney.
The machine was repaired, and all polygraphs used by the Sheriff's Office were replaced in 2010 with the updated LX5000 model, according to county attorney Josh Gruber and Lt. Matt Averill, a polygraph technician for the Sheriff's Office.
Averill said in an email that the department had noticed "the (electrodermal activity) problem with the LX4000; however, that problem seems to have been resolved in the LX5000."
Gruber said Friday the problem was detected in only one of the department's machines -- the one Averill used -- and was repaired.
The Sheriff's Office used LX4000 machines for eight years, from 2002 to 2010.
Gruber said the Sheriff's Office replaced the obsolete LX4000 in 2010 with the new LX5000 model made by the same manufacturer, Lafayette Instrument Co. Averill said in his email that the Sheriff's Office has been a Lafayette customer since 1999, when it purchased the LX3000.
Gruber said an official statement from the Sheriff's Office would be forthcoming. However, by Saturday it had not arrived.
One of the department's senior officers is a regional sales representative for the company. Gruber said last week that Capt. Toby McSwain's off-duty work for Lafayette was approved by the Sheriff's Office when McSwain began working for the company in July 2003. It does not present a conflict of interest, Gruber said.
A former polygraph examiner for the Sheriff's Office, McSwain now oversees the Southern Enforcement Branch of the Sheriff's Office and is the chairman of the board for the American Association of Police Polygraphists.
McSwain acknowledged in an interview that he'd recommended that the Sheriff's Office buy Lafayette equipment, but he said he wasn't directly involved in the purchases.
McSwain didn't collect sales commission on the purchases, Gruber said. As a result, he had no conflict of interest under state law. McSwain was paid a commission by Lafayette for other sales in South Carolina and North Carolina, and he filed the proper disclosure with his superiors, Gruber said.
McSwain declined to say how much he was paid for those sales.
"It's not a business that you can retire early on," McSwain continued. "At least for me."
Gruber added that he wouldn't be concerned if McSwain had recommended that the county buy polygraphs from Lafayette. "We would rely on him because of his history and background in the field," he said.
Attempts to reach Sheriff P.J. Tanner for comment were unsuccessful.
The Sheriff's Office is the only law enforcement agency in the county that administers polygraph tests.
Follow reporter Matt McNab at twitter.com/IPBG_Matt.
McClatchy Washington Bureau staff writer Marisa Taylor contributed to this article.