In my travels today, i saw a billboard for this. man if only i had the time!
http://www.semgulf.com/dinner_mystery.htm
Looks like it’d be a big blast.
http://www.trains.com/community/forum/topic.asp?TOPIC_ID=66965
I rode this train last week while on vacation, please see my trip report at the link shown above.
I thought this was going to be a thread about what’s going on in the Diner lately. The cat has been miffed!
There is also one in Michigan www.murdermysterytrain.com operated be the Adrian & Blissfield Rail Road.
Also a murder mystery train in New Haven, KY at the KY Railway Museum, its a blast too…details at www.kyrail.org
It is a very fast running railroad- with an operating range of approx. 15 miles rail restrictions keep the trains running at 11 mph ( i believe) so they really whiz by and it is hard to see them when they go by… 
also the michigan star clipper train in walled lake mich wasn’t bad either.
stay safe
joe
Hey now !
Dont forget about the Austin Steam Train in Burnett,Tx.
PS Their running an RS?Black Widow scheme until the steam loco is reblt…
The Adirondack Scenic ran some murder mystery trains out of Utica this fall - they were well attended. Dinner was at a restaurant halfway through the trip, but the ‘show’ went on for the whole thing. I didn’t work them, but a co-worker took the ride and thoroughly enjoyed it.