LINCOLN, Neb. (AP) — Lincoln Public Schools will spend more than $3 million to make sure 32 schools in the district have secured entrances.

They are the last of the district schools to have physical barriers put in place between the entrance and the rest of the school. But it may not be an easy task. Older buildings have entrances that are far from school offices, making it difficult to place security in an ideal location. Another obstacle for placing security is that many visitors use doors that are convenient than the main entrance.

The project is one of the security measures implemented after a man walked into an elementary school about a decade ago and sexually assaulted a boy in a bathroom.

The district has been securing entrances since 2006.