Police training for building searches emphasizes safety. Suspects who are hiding usually have the tactical advantage. For example, when you open a closet or attic door, you’re backlit, making you an easy target for a desperate suspect. To protect yourself and others, always follow the procedures you’ve been taught.

One important step is to know the layout of the building. Is there more than one entrance to an attic, basement, or crawl space? You may be able to use that information to your advantage. If the owners aren’t available for questioning, consider that nearby buildings may have similar floor plans, especially if you’re searching a unit in an apartment building, condominium, or housing development.

Look for clues to where the suspect might be hiding, such as disturbed cobwebs, a pool of dust, a trapdoor awkwardly replaced, wire mesh that’s been pulled away from a crawl space, or broken shrubbery. Be sure to look up as well as down: A suspect can shoot from an overhead air vent—and falling bits of insulation might be a telltale sign of a hiding place.

Don’t assume that rushing to apprehend the suspect is the best course. Experienced officers say that the urge to take down a suspect can be especially strong if he managed to get away from you during a search. If you’re embarrassed about a mistake, you’ll naturally want to get it right the second time. But before you make your move, consider which is worse: Feeling embarrassed or dying from a gunshot wound.

Remember that time is on your side. Sometimes hunger, thirst, pain, or the need for a bathroom will prompt a voluntary surrender. Or you can coax a suspect to give herself up by using pepper spray or playing loud, annoying music. Some officer teams have captured suspects by announcing, “We know you’re in there, and we’re coming for you” even when that wasn’t true. Pretending there’s a canine with you might also flush out a suspect.

Often the best course is to wait for a tactical team to perform the search. The team can use technology such as thermal devices, throw robots, and pole cameras to pin down the suspect’s location, and they are trained in effective tactics for capturing him or her.

As is so often true of police work, basic principles—time, training, and professionalism—are the keys to a safe and effective search.