Why is Wes Moore 2 in jail in The Other Wes Moore?

In The Other Wes Moore, author Wes Moore compares and contrasts his life with his supposed "doppelganger," the other Wes Moore. The two men had very similar situations in life and, obviously, share the same name. So why, Moore wonders, did he end up successful while the other man, Wes Moore 2 as he calls him, ended up in prison?
Wes Moore 2 is in prison, along with his brother, for murdering a police officer, a heinous crime. The original Wes Moore, the author, is curious about how their lives diverged so far to that result. He leads the story on a winding path through their own histories to understand the subtle details and choices that separate peoples' lives, and how, in the same situation, he may have done no better.