Will felonies or misdemeanors show on a background check?

An "expungement" erases NOTHING, but rather adds an entry to the case record that it is "dismissed." Your felonies and misdemeanors will show up on the background check. No question about it. Feel free to reqeust a copy of your own criminal history via the California Department of Justice's Live Scan process. Then you'll what they'll see--which is everything. There is no eraser in California.

It matters on what the background check looks for. There are many different types of background checks. Expungement does not delete your conviction, remove it or erase it. It is not like a sponge that removes water that was spilled on a table or the floor. Expungement only changes a complaint's final disposition to a dismissal and the plea back to not guilty. Good luck to you.

I concur with Mr. Finnecy and Mr. Hill.
California does not have a true expungement process. A 1203.4 petition, if granted, will eliminate the convictions and show that the charges were dismissed. However, it will show that there were charges filed.