I’m not so sure. This story makes me think there was some high powered personal anger here, vendetta like, backed by barbaric violence. Beyond some low level drug debt. Begs the question, why would drug cartels even care about this small potatoes workaday guy, scraping bottom sleeping in his truck?? I wonder if the victim had threatened to rat someone out or somehow crossed the wrong people.
I would suggest that his reason for sleeping under a bridge wasn’t to save money but to hide, sound like it didn’t work.