Who is George Anson Phillips from The High Window and what is their importance?

George Phillips is a private detective, though he is not a very good one. Phillips is spotted by Marlowe, as he tails him and asks for Marlowe's help, but he is killed before Marlowe can meet with him. Phillips was hired by Vannier to sell the counterfeit doubloon to Elisha Morningstar. Before his death, he sent the counterfeit coin anonymously to Marlowe.