the role played by the officer to a homocide scene - question clarification

i just want someone to clarify what this question is asking please help!!!

discuss the role played by the first responding officer/s to a homicide scene and the role of the primary investigator upon notification to respond and assume case responsibility.

what exactly is it asking me to do?..

Yeah, this is a tough one!

PART ONE
discuss the role played by the first responding officer/s to a homicide scene --- spend a few paragraphs doing this. You know what this means, so just paraphrase your text book and cite it.

PART TWO
and [discuss] the role of the primary investigator upon notification to respond and assume case responsibility. This sounds like the sort of thing that has a section of your text book dedicated to it. What is the primary investigator supposed to do when s/he is notified of a case?

Search that text book! Answer both questions :-)