Jane's answer is exactly right. I've included the link on Mello-Roos Taxes from the Franchise Tax Board below.
Most of the time, you cannot deduct real estate taxes assessed for local benefits and improvements. However, you can deduct them if they are for maintenance, repair, or interest charges related to those benefits. Some examples of local benefits are:
Public parking facilities
Other similar improvements
To deduct local benefit taxes, you must be able to show the amount of the taxes that are for maintenance, repair, or interest. If you cannot show what part of the local benefit taxes are for these charges, you cannot deduct the taxes.
For more information, you can:
Contact your Mello-Roos District.
Get Internal Revenue Service Publication 17, Your Federal Income Taxes-Individuals, Chapter 24.
You always want to check with a tax professional, but my CPA has told me as far as he is concerned they are a deduction the same as property taxes.
Hope this helps