"This is probably the most important hire I made as sheriff," Long said. "A deputy has to want this job and has to want to work with children in order to be successful."
In February the sheriff's office reassigned some deputies to the elementary schools on a temporary basis.
The Williamson County Commission approved spending $2.4 million to hire and outfit 32 additional SROs on a permanent basis.
The sheriff's office also bought additional patrol cars, equipment and sent the deputies to training at the Tennessee Law Enforcement Training Academy.
Parents of elementary-aged students in Williamson County said they felt better about sending their children to schools with SROs.
"I normally don't have many worries about them," parent Melissa Williams said. "We feel safe at this school, but unfortunately after Sandy Hook there are things that you would not even fathom."
She continued, "Of course the teachers are always there, but its nice to have some one who is in law enforcement and an expert in safety protecting them."
The deputies will park their patrol cars in front of the school to increase their visibility to people visiting the school.
"I think as a parent it kind of makes you feel safe that your kids are taken care of at the school," parent Amy Black, "not just by the staff and teachers but that outside person who can watch over things."
The last 10 SROs are scheduled to graduate from the eight week training program at the Tennessee Law Enforcement Training Center on Friday at 11 a.m.
Rutherford and Wilson County schools will also have SROs at all school campuses.
Metro-Nashville, Sumner and Robertson counties will share SROs.
Montgomery County will have SROs in all schools except elementary schools. The elementary schools will share officers.