Basically someone deleted photos from my dads phone. He doesn't have a sd card and his Galaxy S3 is not rooted. Is there any way to get them back?
I am not sure if you can recover data from internal memory, normal recovery softwares require the device to be in USB/ Mass Storage Mode for it to detect the device to scan. There is one method but it requires the phone to be rooted and it's a long process. If you are interested here is the link to it
Depending on the mobile carrier, the phone may have pre-installed software that has been backing up various files to their servers. For example, my S3 from Verizon has something called Backup Assisant Plus that came with the phone and was on by default. I would check the settings in the phone and the carrier to see if the phone was sold with a default backup system.