There is probably something specific about that year your instructor is looking for, either from your text or lecture notes, so pay attention to that in addition to my response.
The typical 1930s officer was a "beat cop". This means that when they patrolled, they did so on foot, and walked a regular neighborhood, so they got to know everyone "on their beat". This was a good law enforcement method because the officers built a relationship over time with the people in that community, and could focus their efforts on those people and places they knew to be more trouble.
At least one major drawback was that these police did not have portable radios. If they got into a scrape with a perpetrator, they were on their own. Because of this and public opinion of the times, police were given more latitude than they are today in terms of how they decided to deal with situations.
In the modern day, police are more mobile, better armed, better trained, and don't go anywhere without at least one other officer as backup. They are expected to patrol larger areas, use much more modern technology, employ a wide range of non-lethal force (as opposed to the mere nightstick alone for earlier times) and are much more likely to be bilingual.