Through the raven's eyes, Leonard saw several police officers jumping down from the window that had just been opened, and then they pressed Scarface onto the ground and put handcuffs on him.
During this struggle, a pistol fell from Scarface's body, and at the sight of the gun, the police officers visibly became more tense.
Although the United Kingdom in this world had more relaxed private gun ownership laws than the UK in Leonard's previous world, there were still various restrictions.
For example, guns and bullets must be separated during transportation, and some areas prohibited guns altogether. Violating these rules could result in the revocation of one's license and possibly imprisonment.
So even if these people had no other charges, illegally carrying firearms was enough for the police to take action, especially since they were in the city center, carrying six or seven guns, some of which were illegal.