Found iPhone 4S Smithfield

Found a black iPhone 4S in the playground in Smithfield Square beside the Luas stop on Saturday 11th April around 11pm. No case, a few light scratches on back and screen, home button is a bit out of place and doesn't always work when pressed. Locked and was on airplane mode when I found it and no picture on the lock screen, but briefly after being restarted a picture of a wave appeared and then disappeared as if it has been reset. Says sim is locked and was dead when found.