The survivor was a store employee.
http://www.suntimes.com/news/metro/775862,survive020408.article
And now, as many of of have suspected, they are linking the killer to one of the victims.
http://www.nydailynews.com/news/us_world/2008/02/04/2008-02-04_one_of_five_women_in_illinois_bloodbath_.html
Makes sense.
A typical robbery generally doesn't involve multiple murders. Especially one of this type where the amount of cash on hand would not be large.
If there is a connection between one of the victims and the suspect, they already know who the suspect is, and probably have known the ID of the suspect since day one.
The body of the article you linked doesn't match the headline. Not your fault of course.
The headline screams 'linked' when the article says 'may have'. Meaning they don't know.