SAN FRANCISCO (AP) — New court documents filed Tuesday allege San Francisco's recently elected sheriff mistreated his wife on two separate occasions last year, and told her he would attempt to gain custody of their young son because he was "very powerful".

Sheriff Ross Mirkarimi was charged Friday with one count each of domestic violence battery, child endangerment and dissuading a witness. Prosecutors say those charges are related to a New Year's Eve incident with his wife.

An arrest warrant affidavit prepared by police alleges that Mirkarimi's wife Eliana Lopez appeared in a Jan. 1 videotape in which she discussed details about that confrontation and another incident earlier last year.

In the footage shot by a neighbor, Ivory Madison, Lopez is crying and visibly upset about the couple's run-in the day before.

Lopez points to a bruise on her right bicep where she said Mirkarimi grabbed her, according to the affidavit.

"This happened yesterday," Lopez tells the camera, according to the affidavit. "Two times in 2011, and this is the second time this is happening."

"I told Ross I want to work on the marriage - we need help," Lopez continues, according to the document. "I (have) been telling him we need help, and I'm going to use this just in case he wants to take Theo away from me because he ... said that he is very powerful and he can do it."

Lopez, a former Venezuelan telenovela star, married Mirkarimi after having their first child in 2009.

The 50-year-old former county supervisor is scheduled to be arraigned Thursday morning and has vowed to remain in office while he fights the charges.

Mirkarimi was booked at San Francisco County Jail, but released on $35,000 bail.