Question about Rambam's view of murder

Guest Post by Eddie

There are some difficult passages in a Rambam I am studying, and I wish to ask if anyone has some knowledge of this material, and what the halacha is (or was).

The Rambam, in Hilchot Rotzeach, Ch4: 1, the Rambam argues that killing a person by mistake, if you intended to kill someone else, is exempt from punishment, as is throwing a stone (or bomb) into a crowd. Rambam Chapter 4              mechon-mamre.org/i/b504n.htm

 Here the Raavad points out this was a minority opinion of R' Shimon, and hence is not halacha. So this point is presumably not like the Rambam.

In Halacha 6 he writes: If ten people strike a person with ten different sticks and he dies, they are all not held liable for execution by the court. This law applies regardless of whether they struck him one after the other or they struck him at the same time .This is not disputed by Raavad, is it therefore halacha?

The problem is that this is not at all logical It means that, in a time when we have a Sanhedrin vested with capital punishment authority, murder becomes a very easy crime to commit - simply hire a gang of killers, and you are "patur".

One answer, or counter argument, might be the case of Pilegesh sh' b Giveah.  (Judges Ch. 19-20) where a gang of thugs attack a woman and kill her.  This leads to a war to wipe out the offenders, which ends up in 25,100 Benjamites being killed.  But Rambam might argue that this was a case of gang rape of a pilegesh, not of outright murder.

A further problematic halacha, 10, says that we can openly kill an apikorus, or even someone who brazenly commits an aveira. This can be done in public without need for Judge or Navi. 

What happens if someone decides to kill a woman who won't move on a bus, etc?

Furthermore, the Torah punishment of execution  only applies to certain sins. Where is the force of this halacha, with regards to sins that are not capital crimes, eg shatnez.   Can I kill someone for sowing kilayim in his farm?   The Chazon Ish has already stated that this particular halacha, or the continuation of it no longer applies , since today there are not wilful apikorsim. As far as I know, no Orthodox person has ever used this halacha to kill a reform, an atheist, a Bible critic etc, certainly not in the last 300 years.   The only exception might be Yigal Amir wrongfully shooting Rabin – but this was not because he was a heretic, but that  Rabin had been called a rodeif – which is another issue altogether.

The points I make are not suggesting any final psak halacha, and not attacking any Gedolim or Rishonim.  What I am trying to understand is the practical implications of these halachot, and whether they were ever (or will ever) be implemented?