The instability of the economy has decreased the prices of homes significantly. Since June 2006, the height of the housing market's peak, residential property values have dropped 30 percent in the top 20 city markets of the United States, according to Alex Barron, founder and president of the Housing Research Center. Given the circumstances, an increasing number of homeowners have become landlords providing units to a market currently preferring rentals over ownership, HeraldNet reports. To help landlords conduct their operations more efficiently, the Snohomish County Apartment Operators Association held lectures. Christopher Benis of Seattle, Washington-based Harmson, Benis & Spence, revealed the one big mistake often made by landlords today. Creating a save environment in an apartment complex is the responsibility of the landlord and begins with a detailed background screening process. While it is common practice for a landlord to perform a background check on the primary renter, Benis informs that many times additional friends and families of the renter move into the apartment unscreened. This is both unsafe and creates harm's a landlord's reputability. If background checks are performed consistently and it becomes standard practice, an increased trust builds between tenant and landlord.