"Military Policeman At Pearly Gates" joke

St. Peter was standing at the Pearly Gates when a man walked up.
“Welcome to Heaven, my son. What did you do with your life? ” asked St. Peter.
“I was a policeman, ” replied the man.
“What kind of policeman were you? ” St. Peter inquired.
“I was a vice officer. It was my job to keep dangerous narcotics out of the hands of children, ” explained the man.
“Excellent, my son. You may pass through the gates, ” said St. Peter.
A few seconds later a second man walked up.
“Welcome to Heaven, my son. What did you do with your life? ” asked St. Peter.
“I was a policeman, ” the man responded.
“What kind of policeman were you, ” inquired St. Peter.
“I was a traffic cop. It was my job to keep the roads and highways safe for travelers, ” answered the man.
“Very well done. You may pass through the gates, ” St. Peter said.
Moments later, a third man walked up.
“Welcome to Heaven, my son. What did you do with your life? ” asked St. Peter
“I was a policeman, ” he replied.
“What kind of policeman were you, ” St. Peter asked.
“I was a Military Policeman, Sir, ” responded the man.
“Excellent, my son. I have to leave for a short while, watch the gate will you! ” said St. Peter.