From: "Phil Payne" 

Actually, it's now a lot more in most cities.

http://www.thisislondon.co.uk/news/article-23378504-details/Police+release+CCTV
+pictures+of+murdered+prostitute/article.do

These are on a train.  All our local buses now carry them, and the drivers
have DNA kits on the vehicles.  If they have a problem and think they have
any DNA traces, they can secure the evidence even before the police arrive.

--
  Phil Payne
  http://www.isham-research.co.uk
  +44 7833 654 800

--- BBBS/NT v4.01 Flag-5