Police arrested Lu at about 8:30 p.m., long after a medical clinic typically closes, Balian said.
"What we would request from the public is if you see suspicious activity at a medical clinic, such as if it's open at 9, 10 or 11 at night, that should raise a red flag," Balian said. "There's a good chance their operation is a little more than a massage parlor."
Wednesday's was the seventh such arrest of an alleged prostitute in the last year on Honolulu Avenue and would seem to be part of a pattern of such arrests in the Montrose/La Crescenta area, Balian said.
In August, for instance, a 42-year-old woman was arrested on suspicion of prostitution at a La Crescenta business — the sixth arrest for similar activity along Honolulu Avenue since December 2005, police said.
That arrest was made after an anonymous caller tipped off police that a massage parlor was being operated in the 2900 block of Honolulu Avenue, Balian said. When police checked the address, they found that permits were never filed for the business and there was no name on the building advertising it, he said.
Last December in Montrose, police arrested Qing Wang, 46, of Fontana; Mei Ling Yu, 45, of Montrose; Feng Wen Liu, 55, of Monterey Park; and Li Juan Sun, 48, of Monterey Park on suspicion of providing sexual acts in exchange for money.
Police believe the women were operating a prostitution ring out of Royal Acupuncture Clinic and Integrative Pain Clinic.
About a month later, 37-year-old Hui-Yuing Liang, of Alhambra, was arrested on similar charges in connection with the same prostitution ring.
Three of the women's cases are pending, but police have reason to believe that four of the women who were arrested have fled to China, Balian said.
Balian said landlords bear some responsibility in making sure massage establishments and clinics are legitimately run, with proper licensing and documentation.
Lu was booked at the Glendale Police Department and released on $2,000 bond.
She is scheduled to appear in Glendale Superior Court on Jan. 19.
RYAN CARTER is City Editor. He may be reached at (818) 637-3220 or by e-mail at ryan.carterlatimes.com.