This excellent article in the NY Times discusses the unusual punctuation in the 2nd amendment with regards to the upcoming Supreme Court case.
A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.
Adam Freedman makes the point that punctuation was a relatively new phenomenon in the 18th century and was very loosely applied and in fact was inadmissible in legal statues under English law.
Refreshing though it is to see punctuation at the center of a national debate, there could scarcely be a worse place to search for the framers’ original intent than their use of commas. In the 18th century, punctuation marks were as common as medicinal leeches and just about as scientific. Commas and other marks evolved from a variety of symbols meant to denote pauses in speaking. For centuries, punctuation was as chaotic as individual speech patterns.
Ultimately he suggests that the second amendment should be read without the commas. Which would indicate that it refers to an organised militia and not the general populace.