Officer Marie McCann is a policewoman from Mountaineer, Vermont (fictional city) who once worked closely with Alva on a paranormal case involving the infamous Mothman. (This is all fanfic stuff, not something that appeared in the series.) Her model is a younger version of actress Heather Locklear. If you'd rather imagine her looking like someone else, it doesn't bother me - I can't police yer brain. ;)
Character Is: Old friend and old flame of Alva's.
Character Appears In:
You Can't Help Who You Are by Laurel Wilson
Spoken to on the phone in "Fate is an Engineer" (reached through the Only After Dark page.
This is a pretty good representation of what Marie's police uniform looks like, especially the hat. Here it is modeled most generously by Tori Amos. ;)