Per http://www.wsbt.com/news/local/breaking-police-respond-to-stabbing-at-amtrak-station-in-niles/30085188 the perp had a ticket from Chicago to Flint, so this train was the Blue Water (Chicago-Niles-East Landing-Flint-Port Huron), going no closer to Detroit than Flint.
Here's Amtrak's Michigan service...
http://www.amtrak.com/ccurl/8/305/Michigan-Service-Schedule-102714.pdf
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