The problem Muz with your question is that you are asking a reasonable question based on logic.
Sick minds don't work that way......

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How AMBITION caught him

As mentioned earlier , Dellen had a tattoo on each wrist which says AMBITION

Police had a couple of breaks early in the case .... normally they pay very little attention to missing persons reports or vehicle thefts , they get hundreds every day

But when Tim Bosma did not return from the test drive his family and friends knew something was amiss and immediately began a publicity campaign that was picked up by local TV stations ...

A groundskeeper picking up litter along a street found a cell phone which belonged to the missing man so he gave it to police who traced the last phone call to an anonymous disposable phone used by the kidnappers who test drove the truck

Turns out the culprits had also used the disposable phone and test driven a similar truck a day earlier so police interviewed the seller , who said the two guys had been there , but the truck owner was 6'3 and 300 lbs so they did not try to overpower him and steal his truck

He gave the same description of the two guys as did Tim Bosmas wife who watched them drive off with her husband , but he also noticed the small AMBITION tattoo on the wrist and told police who put the information on the evening news.

A patrol cop in a different town saw it on the news and remembered a routine patrol stop a couple of years ago where the driver had tattoos like that so he looked up his notes and gave detectives Dellens Millards name and the noose began to tighten.