At the very least, they all need to be kept informed of what is being done, and why, and how this will effect them directly. Parents, in particular, should be helped to understand that the measures are not intended to obstruct their involvement in school life. Parents want their children to be safe, but they don't want to feel unwelcome. The most effective way of avoiding this tension is by taking a positive approach, emphasising the ways in which we will work with them for the good of their children. This will involve keeping them informed, and providing them with opportunities and guidance about supporting their children and making sure that their children are safe.
School security is part of the implicit contract between teachers and parents.
But it is only part of that contract. If we emphasise that part, then what we do with good intentions could have some unlooked-for side effects. If we emphasise the whole, it might help us focus again on what we mean by partnership.