In the US in 2050, I imagine that policing will not be all that much different from what it is today.
I think there will be a couple of differences. First of all, I would think that even ordinary police officers (as opposed to detectives) will need to use a wider range of computer technology than they do today. They will need to be trained for this.
I think the major difference in 2050 will be one that will not be technological -- it will be more social. By that year, the population of the US will be much more diverse. If your organization is in a racially diverse area, your officers are going to need to know how to deal with a loto of different kinds of people. You will need to hire people who are able to do this and/or you will need to train them in dealing with people from the appropriate other cultures.