California sets few rules for charter school oversight. A new report offers improvements.

California lawmakers have been told over the past two decades that it needs to improve how it oversees charter schools, but the state has not yet made significant changes to its laws and policies about how to hold a charter school accountable while it’s operating.

Those shortfalls have cost the state, which has seen recent cases of fraud and other improper spending by certain charter school networks. San Diego prosecutors said a lack of charter oversight was prominent in the A3 charter school fraud scandal of 2019...