MORENO VALLEY, Calif. -

Moreno Valley Mayor Pro Tem Marcelo Co resigned today, a day after being arrested and charged in a fraud case.

Co, 64, faces eight felony counts -- including making false claims, fraud to obtain aid and grand theft exceeding $400 -- for allegedly improperly collecting income from a state program that provided funds for the in-home care of his mother, according to the Riverside County District Attorney's Office.

He posted a $15,000 bond on Monday and is expected to be arraigned Wednesday at the Riverside Hall of Justice, according to jail records.

Co, who has represented Moreno Valley's southern end since his election in November 2010, submitted a resignation letter dated Aug. 11 to Mayor Tom Owings.

``The council respects Mr. Co's decision, and we will work collectively to assist residents and businesses in that area of the city during this interim period,'' Owings said in a written statement.

The criminal case against Co involves the In-Home Supportive Services program, said John Hall of the Riverside County District Attorney's Office.

Co is suspected of improperly collecting nearly $15,000 in state funds, Hall said.

``Co is listed in that program as a provider for his mother and therefore (he) collected IHSS income for her care,'' Hall told City News Service. ``It is alleged that it would have been impossible for Co to provide care to his mother during certain periods of time because she was not in the United States while, during those periods of time, he was in the U.S.''

Co was already the focus of an investigation by a regional corruption task force, which searched his home and those of four other council members on April 30. The investigation led to a recall effort against Co and other council members, according to The Press-Enterprise.

Hall said Monday's arrest was ``entirely separate from any other investigation involving Mr. Co.''

The Moreno Valley City Council will hold a public discussion about filling Co's Fourth District seat -- his term would have run through November 2014 -- at a future meeting. The council has up to 60 days to make an interim appointment or call a special election.