One third of those polled said that statistics show a persistent racial bias by law enforcement officers.
"The men and women coming into police have to have a good solid education," Couper said. It will help them to know "how to control the use of force, when they legally can use force, and to be respectful to all people."
Couper argued "unconscious cultural bias" has become a "social plague" in many countries.
The former police chief, who has been advocating a higher education requirement for police employment for the past 40 years, said college will help officers understand "how the world works," by learning more deeply about history and psychology.
"It is absolutely important that they [law enforcement officers] recognize the subtle unconscious bias that we all have, and I think that is the key to this right now," Couper added.
At present, to become a police officer a US citizen must be at least 21 years old, have a high school diploma and complete a police academy training course.
In recent months, police forces in the United States have been strongly criticized for excessive use of force, particularly in the wake of well-documented killings of unarmed black men by white police officers.