The correct execution of a perfect murder

Its always raining when body's are found at least that's what you normal people think but that's not true usually it's sunny the sun firing down on the body creating the cooking corpse to have a nauseating smell. That's another thing people forget about the smell of a roting body overtakes everything from clothes to cars filling it with an odor you will never forget. But today that's not the case today laid out in front of me in a disconnected puzzle like position in the pouring rain was a body a man late thirty's. The man's clothes were paced in vacuum sealed bags with his wallet placed on top I.D ,drivers licence and money all still there Christopher Dodd was his name he was a butcher from down town "this was also with the body" a junior officer passed me a laminated note that was covered in a sticky substance what it read was like no other case I've seen 'hello Mr Rollins thank you for tending to Christopher so quickly you see he fell sick recently and I had to put him out of his misery luckily he could donate his most intresting feature for me see you round my freind sincerely Dr mallard' that sick f**k the note was there to start this murderous bastards down fall. Three things stood out to me on this letter though how did he know my name ,what did he take from the body and why would he sign his name. These rang over in my head as I waited for the results to come back from the morgue what game was this guy playing. About four hours later the results were placed on my desk flipping through them looking for anything out of place the only thing 'missing' from the body was the man's cornea a strange thing to take but after being a homicide detective for so long killers taking trophies wasn't new to me it's common with people of their nature but this was different to remove a cornea would require accuracy. Accuracy wasn't something that was new to the killer the entire body had been skinned and had the bones removed to perfection the the joints broken till every last bone had been separated but then re laid out in the alley for the crime scene it screamed Ocd to me even the laminated note. This killer had time he wasn't worried about being caught out before he Finnished his 'work'. This precise behavior settled me some how as that gave me confidence that at one time at some point he will make a mistake he's already made one. The way he'd found my name I knew how he would have done this through the newspapers three years ago when I arrested a mafia boss in a sting. This was my life line if i visited Dr Mallard and found the paper I could use it to take him down.