A 10-year-old from Darlington helped police solve a crime by snapping a pic of a thief red-handed and putting it on a social networking site.
Alex was in a car with his dad when he spotted the thief snatching a phone from a pedestrian.
He took a photo, posted it on Twitter and then went to the police station to show them his evidence.
The snap helped Durham Police catch the criminal who admitted to the theft and had to pay a fine.
Alex said: "I got my dad's phone and took a photo and my dad put it on Twitter.
"The lad whose phone it was was just listening to music then when his phone was taken he started running after the thief.
"I just thought we can't let him get away with it as phones cost a lot of money."
Durham Police said Alex showed spirit but they also reminded any witnesses that they should bring evidence to the police before putting it online.