Another way I like to catch people in the act is with these little guys:
http://budk.com/product.asp_Q_pn_E_XL109
Just get some small wooden stakes (a few inches tall), a bag of my favorite little "pull string alarms", and some fishing line. Rig a perimeter around your truck with it. That when when they walk up to it they'll trigger it, hopefully not returning. Trust me, at 85 decibles she'll think she's getting shot at (oh thats right... You cant have guns in Canada
)
and if your vigilant with your camera you might get out there in time to see them scampering off. And just remember, if you lived in Texas you could shoot the bitch.
I need to move to Texas.