Gladys Knight Sings 'Happy Birthday' To Police Officer Gladys Knight Sings 'Happy Birthday' To Police Officer Gladys Knight Sings 'Happy Birthday' To Police Officer Gladys Knight Sings 'Happy Birthday' To Police Officer Gladys Knight Sings 'Happy Birthday' To Police Officer Gladys Knight Sings 'Happy Birthday' To Police Officer Gladys Knight Sings 'Happy Birthday' To Police Officer Gladys Knight Sings 'Happy Birthday' To Police Officer