The New York Times reports that in recent years lenders have increased fraud-prevention investigations and checks on mortgage applications.  According to the research firm CoreLogic, estimated fraudulent residential mortgage originations will total $7.4 billion in 2011; the number is nearly 40 percent lower than the $12 billion in 2010, though the company attributes the decline to a drop in mortgage volume.  Fraud-prevention measures look into where you work and live, how you use credit, and more.  Applicants for residential mortgages can expect increased scrutiny if they have recently made a large bank deposit, the purchase property address is a distance from their job, they incur new or have undisclosed debts and/or issues related to their income.