Back when dinosaurs roamed the planet law enforcement had to look for witnesses, bystanders, and get on their hands and knees to look for the slightest hair or clue that would help them crack the case. They still do all that stuff today, but one of the first things they look for are security cameras in the vicinity of the crime scene that will tell them the rest of the story.

In Philadelphia, homicide detectives investigated a woman who went missing and was eventually found murdered. After the discovery law enforcement began tracing back her steps and detectives started looking for cameras along her route of travel.

“In the days after [the murder], residents provided police with a list of cameras at local businesses and apartment buildings. Soon, detectives were working around the clock, viewing hundreds of hours of footage taken by dozens of cameras.”

Cameras caught the suspect as he was on his bicycle in the area of the murder. One video showed the suspect biking past the victim and him making a U-turn on his bike and began to follow her.

“One recording provided a clear view of the suspects face. The day after it was released to the public, police got a tip that led to him.”

Joran van der Sloot, the main suspect in the Natalie Holloway murder confessed to the slaying of a 21-year-old woman in a Lima hotel room. Hotel video caught him checking into the hotel, walking in the hotel room with the victim and him walking out alone. She was discovered a day later. Video certainly helped make his confession possible. Too bad they didn’t have video cameras on the beaches in Aruba. The Peru victim may still be alive.

Cameras are everywhere. Some people call this an invasion of privacy. I say the more cameras the better. We are on camera at most retails stores, banks, ATMs, busy intersections, highways, downtown areas and in neighborhoods. We are a video camera soaked society and it’s a good thing. It keeps the honest people honest and the bad guys in-check or in jail.

Set up security cameras to monitor the perimeter of your home. Security cameras can send off an alarm triggering additional lighting, sirens and alerting the home owner to a potential breach via text and telephone calls. I can immediately see my cameras via my iPhone. Cameras inside the house are necessary as well. Wire your home to show all doors and living spaces to ensure home security. Once you take the leap you wonder how you lived without it.

Robert Siciliano personal security expert to ADT Home Security Source discussing Home Security on NBC Boston. Disclosures.