He's screwed:

"felony murder": If you participate in a bank robbery and your robber buddy kills somebody . ; You can be charged with a homicide.You had a hand in it.
from the wiki:

("The rule of felony murder is a legal doctrine in some common law jurisdictions that broadens the crime of murder: when an offender kills (regardless of intent to kill) in the commission of a dangerous or enumerated crime (called a felony in some jurisdictions), the offender, and also the offender's accomplices or co-conspirators, may be found guilty of murder.

The concept of felony murder originates in the rule of transferred intent, which is older than the limit of legal memory. In its original form, the malicious intent inherent in the commission of any crime, however trivial, was considered to apply to any consequences of that crime, however unintended.")

[link to en.wikipedia.org (secure)]