DCMedia by default doesn't remove expired content from a player.
You can configure DCMedia to do this for your content by following these steps:

1. Click the publish tab to view or setup a playlist.

2. Select your playlist and click "Populate playlist with assets".

3. Add content to the timeline or select existing content, then click the "duration and playback" settings icon.

4. Ensure a valid from and to date/time is set, then check the "Delete after expiry" box.

5. Click "Ok" to confirm these settings.

6. Do this for any content you wish to be deleted from your media player when it is no longer needed. Keep in mind, the asset will remain in the playlist even after the expiry date/time.