Gamdin is a Dorgeshuun goblin involved in a court case against Vidar Ilknot, a H.A.M. member. He was assaulted by H.A.M. agents when wandering around Lumbridge at night.
If you choose to defend Vidar, it will be revealed that Gamdin entered the H.A.M. Hideout and pickpocketed several agents, including Vidar, until he was caught and thrown into jail. If Vidar is prosecuted, it will be revealed that Gamdin had bought all the items he was found with from various shops in Lumbridge to bring back to his family as souvenirs and that, when walking around some ruins, H.A.M. agents violently abducted Gamdin.
The crime scene, with Gamdin in the jail cell.