Law & Order: Legacies joins the ranks of Wallace & Gromit's Grand Adventures as another Telltale series that is no longer available for sale from digital storefronts. If you already purchased the game you should still be able to download the game from the digital storefront where you purchased it. Otherwise, there is no longer any way to purchase it digitally as the game has been removed from sale on Steam, the Telltale store, and iTunes.
Luckily, all hope is not lost, as like Wallace & Gromit's Grand Adventures, the PC version was released at retail, so it's still available while supplies last for people who still want it. However, unlike Wallace & Gromit's Grand Adventures, the retail version of Law & Order: Legacies was only available in the United Kingdom. So, outside of eBay, Amazon UK is your only chance to get it now.