Thomas and Alito are "law and order" conservatives. They will almost never vote to find any search unconstitutional. Scalia can also sometimes be very pro-prosecution in criminal cases, but also sometimes (like today) has a bit of a libertarian streak.
On the "liberal" side of the Court, Kagan and Sotomayor are usually pro-defendant in criminal cases, but Breyer (often) and Ginsburg (sometimes) can be pro-prosecution.
That is was I was thinking. Justice Scalia has a Libertarian bent at times. It is interesting to read him. Whether or not you agree, his thoughts are always very detailed.