Does the reporter's opinion matter?

A reporter is supposed to keep their opinions out of a story and never use "I", "we", or "us". But, aren't there times when the reporter is an expert on the subject he is reporting one. Who else has followed or researched as much on the subject as the reporter has? If the reporter is supposed to have expert knowledge on the subject doesn't that make him qualified to speak on it? And, what about those situations where everyone knows what happened, but there just isn't enough evidence to convict on it?

A reporter is taught to research, interview, and dive into his story. But, at the same time he is supposed to keep himself out of it. Police use their opinions when investigating a crime. Reporters should be allowed to use theirs when reporting one. They have a voice to be heard and need to use it. While not every reporter is out there working for the good of the human race, every reporter's voice is still important. 

How can a reporter report on something cruel and terrible without using their own opinions?