First install package rdfind: 
<code>sudo apt install rdfind</code> 

To get a list of duplicate files in our Photos directory, but not take any action, we can tell rdfind to perform a "dry run":

<code>rdfind -dryrun true Photos </code>

if we want to really remove copies of duplicated files, we can run the following command. This is destructive and will wipe out any duplicates the rdfind tool locates:

<code>rdfind -deleteduplicates true Photos </code>