Your deleted messages may not actually be gone.

So how are the deleted files discovered, why are they still on your device, and how long are they stored there?

When we extract data from mobile devices, we do so in a variety of ways. To access deleted files, we use a method called physical extraction. In this process, an analyst will use special tools and devices to extract everything within the file system of the device, as well as search through the freespace. Essentially, when something is deleted, it does not immediately disappear. Instead, your phone deindexes it. This means it stores it, but does not know where it is stored. That data is stored in the freespace of your device. However, eventually, your phone will overwrite the deleted data as it uses the freespace. Once the data has been overwritten, it can no longer be accessed through any form of extraction. The amount that you use your phone impacts the amount of time it takes to overwrite the deleted data.

With all of this being said, there are many different factors that go into recovering deleted messages or files. These factors include variables such as the device itself, operating system, and the application used to record the data.