How are police interrogators educated?

That’s one query that retains popping into my head whereas watching true crime documentaries and such.

Like do they follow on one another?

I think about the officers interrogating homicide suspects are fairly skilled. However how do they get the expertise? Do they sit subsequent to extra skilled officers and in some unspecified time in the future simply begin interrogating on their very own? Possibly begin with folks accused of lesser crimes?

So many questions

submitted by /u/VetoSnowbound