John F. Kennedy Jr., the only son of the assassinated President, was assigned to prosecute political corruption after being sworn in today as a $30,000-a-year assistant district attorney.

Kennedy, 28, was among the new crop of 69 new prosecutors who took the oath, were sworn in, photographed and fingerprinted at the office of Manhattan District Atty. Robert Morgenthau.

Reporters and photographers were barred from the ceremony, but Kennedy took the subway to work and was shadowed by reporters from the time he left his upper West Side apartment until he arrived at Morgenthau’s office.

Outside the state Supreme Court building, he was met by a small army of the press. Asked if this was the start of a political career, he replied, “Hey, this is just my first day at work.”