<human>: Gist of it is, an old friend of mine was recently arrested in Arizona. From what I know, the charges are murder and aggravated robbery. I was close friends with this person in high school but moved out east for college and lost contact with him. But then this thing happened, and his parents are reaching out to people they know were good friends with him to write character witness statements. He was one of my best friends back then so I feel like I owe it to him to do this.

But I have a few questions first: How much of an effect can this actually have? Where do I even start? Most of the sample ones i read sound like they were for much less serious charges and would just sound odd if I followed that template. And is there generally a realistic chance that someone could get called to testify for something like that?

Can you summarize the given text in a few sentences?
<bot>: Friend is being charged with some serious shit. I got asked to write a character statement. Have no idea what that entails