Property Tax Question, Los Angeles, CA

I purchased a property around the beginning of July this year. I received a Supplemental Property Tax Bill and an Annual Secured Property Tax Bill. Both equate to ~10k in taxes (3k +7k). I owned the property for ~3.5 months now and it's very confusing. Do I need to pay the supplemental if my ownership started after June 30th? Thank you. Any and all insight is greatly appreciated.