Lester Zygmanik was charged with murdering his brother, George after George was severely injured in a motorcycle accident. George did not want to live his life as a quadriplegic and asked Lester to kill him; Lester did as his brother asked. If you were a juror in this case and you were making decisions based on black letter law, you would decide that Lester is

Black letter law is used to describe established legal rules that are normally not subject to any kind of reasonable dispute. For example, assault generally has a clear cut technical definition, and thus trying to argue yourself out of this type of conviction is harder. Another term that is used to describe this rule is hornbook law.

Thus, if you're using this approach in determining Lester's fate, you would give a guilty verdict to him.