“Suspicious activity reports,” or SARs, filed by depository institutions reporting questionable mortgage activities increased significantly in 2005, according to the latest report on SARs filings by the Financial Crimes Enforcement Network. According to FinCen, an enforcement agency in the Treasury Department that tracks money laundering and other financial crimes in the U.S. and abroad, more than 3.1 million SARs were filed as of Dec. 31, 2005. Depository institutions accounted for more than 2 million…