Prevention of Crime Against the Elderly Act - Amends the Omnibus Crime Control and Safe Streets Act of 1968 to require that comprehensive State plans under such Act include provisions for the prevention of crimes against the elderly. Authorizes the Law Enforcement Assistance Administration to make grants to States having approved comprehensive plans for the development and operation of programs designed to reduce crimes against the elderly, including effective sentencing alternatives and the use of mandatory sentences, and improved offender rehabilitation programs for offenders committing crimes against the elderly.