In the continuing murder investigation of DeKalb resident Lisa Garretson, police are conducting lie detector tests on several suspects.

“We are testing probably about 20 people—some have already been tested,” DeKalb Police Sgt. Chuck Kross said.

Other evidence also is needed to support the tests. “A polygraph is not acceptable in court,” Kross said.

He said no other information about the investigation is available to release.

Garretson, 26, was found strangled to death in her 110 State St. apartment about 9:40 p.m. Aug. 21. After the stangulation, her apartment was set on fire by use of an accelerant, police said.

Garretson graduated from NIU in 1984 with a bachelor’s degree in elementary education. She worked full time at Cardinal Glass, 1651 State St., and part time as a waitress at a local country club.