Paul Khan was a Sorcerer and lawyer, a friend/colleague of Kit Bae. He was in hiding from the Cabals for an unknown reason, Derek Souza remarks that his father said he made a very stupid mistake. Derek Souza and Simon Bae were unable to agree on his name which Simon thought was Pallav Khanna, it's possible this was his real name that Simon had overheard. He appears briefly in the novella Dangerous when Derek discovers his body. Paul's neighbour hadn't seem him since the morning a story was printed in the Albany paper about Derek which mentioned his family enough to identify them.
His body was found with gun in hand, in an apparent suicide. This seems unlikely for multiple reasons; the apartments window had been left wide open during a New York state winter, possibly to hide the smell of decomposition for a time. If Paul was deep in hiding and worried he would be found through his association with Kit Bae it makes more sense for him to run before a connection is found. A neighbour stated that the walls are thin enough to hear a sneeze through so a gunshot would be heard unless it was silenced. As a supernatural, and especially a Sorcerer, Paul is unlikely to have owned a gun to begin with. It is later revealed that Kit Bae was abducted by a Cabal, meaning that Paul was likely found through his association with Kit and executed.