Former Reagan aide Brady's death a homicide, but bringing charges in the 1981 shooting tough

FILE - This March 30, 2011, file photo shows former White House press secretary James Brady, left, who was left paralyzed in the Reagan assassination attempt, looking at his wife Sarah Brady, during a news conference on Capitol Hill in Washington marking the 30th anniversary of the shooting. This week's death of former White House press secretary James Brady, who survived a gunshot wound to the head in a 1981 assassination attempt on President Ronald Reagan, has been ruled a homicide, District of Columbia police said Friday, Aug. 8, 2014. (AP Photo/Evan Vucci, File) (The Associated Press)

The death of former White House press secretary James Brady has been ruled a homicide, but legal experts say bringing a case against his shooter, John Hinckley Jr., would prove difficult.

District of Columbia police say an autopsy states the cause of Brady's death Monday at age 73 to be the gunshot wound to the head he suffered in 1981 during an assassination attempt on Ronald Reagan and its health consequences

Federal prosecutors say they are reviewing the ruling.

Hinckley's long-time attorney Barry Levine tells The Associated Press that bringing new charges against his 59-year-old client seems unlikely.

Tung Yin, a law professor from Lewis & Clark Law School in Portland, Oregon, says it's rare the act that could be considered the cause of a murder occurred so long ago.