Green was arrested Tuesday morning by the Huntington Beach police at the Garden Grove police station, where he has been on the force since 2006.
He is on non-paid administrative leave.
Green is accused of sodomizing a 41-year-old woman April 26, 2009, in her Santa Ana home as she screamed and struggled to get away, officials said.
He allegedly tried to intimidate her and made derogatory remarks during the act.
He had met the woman online and had been dating her sporadically for a short time, officials said.
Green allegedly forcibly sodomized a second woman Nov. 6, 2009, in his Huntington Beach apartment as she screamed and tried to get away, officials said.
He is accused of also trying to intimidate her and making derogatory remarks during the act.
The 40-year-old woman had met Green through a mutual friend, and they were on their first date.
Officials are asking anyone who has additional information or was a potential victim to call Huntington Beach Det. Michael Szyperski at (714) 536-5988 and Supervising Dist. Atty. Investigator Randy Litwin at (714) 347-8794.