The board of education is authorized to enter into an agreement of understanding with a local law enforcement agency to have a school resource officer (SRO) assigned to a school. The SRO must be a law enforcement officer as defined under T.C.A. § 39-11-106, and must be in compliance with all rules and regulations of the POST commission. The SRO is required to complete 40 hours of basic training in school policing within twelve months of assignment and at least 16 hours annually thereafter. T.C.A. § 49-6-4217.  LEAs and law enforcement agencies are not required to assign or provide funding for SROs to city school systems within the county; the provision of security or SROs is considered a law enforcement function and not a school operation or maintenance purpose.  T.C.A. 49-6-815.