Onigo Escapes (central): The Murder of Hector Reeves

There’s been a murder. It happened in broad daylight in Central London but mysteriously, no one saw a thing.

Conveniently (or rather, crucially, or else it would be a rather more challenging game) there have been some clues left behind. Riddles, patterns and whatnot. Can you help us work through each clue and solve the murder?