I came across an article yesterday that was featuring the Irving Police Department in Texas. The local police department was putting on a seminar on Church Security. Every church is not going to have the opportunity to attend a seminar by their local police department; however, they can reach out the the police and asked them for advice on how they could better protect their facility and congregation.
It is important to liaison with your local police and fire departments. Invite them to come and visit your church building. In the event of an emergency you will want them to be familiar with the inside of your building. Hint: Purchase a few pizza's and host an open house for the police and fire department. Having a little bit of food will encourage them to stop by.