You are able to buy "The First 48" on Apple TV as download.
There are no options to watch The First 48 for free online today in Canada. You can select 'Free' and hit the notification bell to be notified when show is available to watch for free on streaming services and TV.
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The First 48 follows detectives from around the country during these first critical hours as they race against time to find the suspect. Gritty and fast-paced, it takes viewers behind the scenes of real-life investigations with unprecedented access to crime scenes, autopsies, forensic processing, and interrogations.