jQuery not parsing JSON properly

The JSON needs to have brackets around it, so it should be:

({"items":[            
  {
   "src": "gallery_item_data_Jc4EaLP6vlwd_large.jpg",
   "id": "83",
   "gallery_id": "30",
   "username": "admin"
  }]
})

You should then be able to use getJSON, as this is the easiest way to get the data as an object. However, you can also eval() the string and that will return an object.