Hello JBOBBY17,
Your iPhone has trusted this computer in the past, as indicated by the fact that iTunes can sync with the device.
The trusted computer or device can access the files and settings of your iOS device. A trusted computer can sync with your iOS device, import photos, access movies and videos, contacts, and other such content, until you disconnect. The data stored on your iOS device isn't exposed before you enter your passcode (if enabled) and choose to trust the connected computer or device.
'Trust This Computer' alert on iPhone, iPad, or iPod touch
http://support.apple.com/kb/HT5868
If you're still unable to transfer photos and videos, the article linked below details some a number of troubleshooting steps that can help resolve this issue.
iOS: Unable to import photos to computer
http://support.apple.com/kb/TS3195
Cheers,
Allen