The Murder of a Large Italian Man in a London Morgue

The body of a large Italian man washed up on the banks of the river Thames. The medical examiner's notes indicate that he was killed before going into the water. Without much evidence to work off, the case starts going cold. How did Luke Peterson and his accomplices get the painting through a locked door without alerting any guards? A week passes before the case gets a new lead, a new thing to investigate.