Depends on the type of crime, and of course we are talking about a hypothetical situation in which time is of the essence.
And this is where the police and social workers face all sorts of uphill struggles - because on the one hand, they have to treat everybody equally (rightly so), but at the same, their resources and time are limited so they have to make 'educated guesses' about where best to start, or where to focus attention, and that invariably means some location / group of people are going to feel targetted.
If you work in child protection, you know that any child, in any social environment is at risk, but proportionally, 'neglect' is a common issue and most often found in deprived areas. If you want to do the best you can, for the most amount of children, that's where you'd put most of your resources. Targetted? yes. Biased? maybe. But I can't see a better strategy.
If you want to tackle knife crime, you have to solve the cause, but if you can't do that, you just have to put your resources where they are needed the most, and that's deprived inner cities, and those locations have a disproportionate number of young black males.
If there is suddenly a terrorist threat in a city, reports of suicide bombs etc, then you can guarantee the police will focus attention on young male muslims. Time is of the essence, they can't treat everybody indiscriminately. They literally have to hedge their bets.