Conversation so far:
Where was Muhammad Ali born?
Muhammad Ali was born in Louisville, Kentucky.
When was Muhammad Ali born?
Muhammad Ali was born on January 17, 1942.
What did Muhammad Ali's parents do for a living?
Muhammad Ali's father, Cassius Marcellus Clay Sr, was a sign and billboard painter.
Who was Muhammad Ali's mother?
Muhammad Ali's mother, Odessa O'Grady Clay, was a domestic helper.
Where did Muhammad Ali go to school?
Muhammad Ali attended Central High School in Louisville.
How did Muhammad Ali get into boxing?
Ali was first directed toward boxing by Louisville police officer and boxing coach Joe E. Martin.

Question: How did the cop get him into boxing?
Self-contained rewrite: How did Joe E. Martin get Muhammad Ali into boxing?