need to stop a truck from cranking

[26Troadster]

i need a little help. my father inlaw has dementia,
and snuck off in his truck yesterday.
drove about 40 miles to the airport thinking he is
still working and was looking for his workers.
he asked a officer where they were and he took my fil
into his care till family could get there.
i know i had a 88 jimmy s15 that if i disconnected
the water temp sender the truck would not start.
i hope it can be this easy on his. his truck is a
08 gmc 4 wd v8. anything easy to stop it from cranking?
thanks in advance.