Commercial Lease Law Insider: Use Surveillance Video to Show Reasonable Maintenance. Install security cameras not only to help you deter and catch criminals, but also to help you prove to a court whether or when a dangerous condition existed on your property. That's important because the length of time a dangerous condition has existed on your property where an accident occurred is a consideration in determining whether an owner acted reasonably. If the dangerous condition existed long enough so that you should have known about it, and you did nothing to make the area safe, the court is more likely to find you at fault for an injury.