You may share SARs with Law Enforcement. The whole reason to submit a SAR is to notify LE. But you'll want to analyze the competency of the LE you'd be sharing with.
PG 79 of the exam manual:
For situations requiring immediate attention, in addition to filing a timely SAR, a bank must immediately notify, by telephone, an “appropriate law enforcement authority” and, as necessary, the bank’s primary regulator. For this initial notification, an “appropriate law enforcement authority” would generally be the local office of the IRS Criminal Investigation Division or the FBI. Notifying law enforcement of a suspicious activity does not relieve a bank of its obligation to file a SAR.
Examples of agencies to which a SAR or the information contained therein could be provided include: the criminal investigative services of the armed forces; the Bureau of Alcohol, Tobacco, and Firearms; an attorney general, district attorney, or state’s attorney at the state or local level; the Drug Enforcement Administration; the Federal Bureau of Investigation; the Internal Revenue Service or tax enforcement agencies at the state level; the Office of Foreign Assets Control; a state or
local police department; a United States Attorney’s Office; Immigration and Customs Enforcement; the U.S. Postal Inspection Service; and the U.S. Secret Service. For additional information, refer to Bank Secrecy Act Advisory Group, “Section 5—Issues and Guidance,” The SAR Activity Review—Trends, Tips & Issues, Issue 9, October 2005, page 44 at
www.fincen.gov.