PHOENIX, ARIZ. ? A man has admitted sexually assaulting a dozen women in a series of rapes that had frightened women across the city during the past 14 months, police said Tuesday.

David B. Wilson Jr., 32, was arrested Monday night at a condominium complex after an undercover officer saw him acting suspiciously, said police Lt. Frank Milstead.

Authorities said he later admitted raping 12 women and was booked on multiple counts of sexual assault, attempted sexual assault, kidnapping and burglary.

Wilson, a self-employed satellite TV dish installer and son of a Phoenix police sergeant, targeted young women in upscale apartment and condominium complexes, and stalked one for months, authorities said.

The first rape happened in July 2004. The next two assaults came in November, followed by two in February, three in April, two in May and two more in July 2005.

Police assigned more than 50 officers to the case once they spotted similarities in the assaults.