These Burner Phones Can Help You Evade Data Snoops
wired.com
wired.com
Notable example: The CIA's Sabrina De Sousa got caught in a similar way.
> Phone records show calls made from De Sousa’s phone to one of the kidnappers eight months before the operation and around the time of the abduction [0]
So: If you really want to leave no usable trace, never ever use the same prepaid sim card in different burner phones, rotate them every so often (physically destroying them after you're done) and only call and be called by other burners.
That's probably a little much, and I would advise someone trying to do this to ensure that this matches their threat model. Unfortunately that's become somewhat harder in recent years wrt to just existing in the digital space.
[0] https://www.washingtonpost.com/lifestyle/style/kidnapping-un...