Recover mistakenly deleted photos from Nikon D3100
Photos and videos captured with Nikon D3100 are stored on a SD card, which is more friendly in terms of photo recovery, the scenario is, after you send the "delete command", the camera flagged that very part of storage as free space and will overwrite it with new data when necessary.
So the key is to avoid overwritten, which means you should stop shooting once the photos or videos were mistakenly deleted.
This is the guide about how to recover deleted photos from nikon d3100
First download photo recovery for nikon d3100, it can also recover video and audio files deleted from the SDXC card of Nikon D3100
Attach your nikon d3100 to computer, and select drive.
Click on scan, after scanning, the software will presents all the photos deleted from SDXC card of Nikon D3100
Select the photo and click recover.
You will have your photo back in a moment of time.