Here's an extract from a site I stumbled upon this afternoon which seems to be implying that the missing key points towards Barnett setting MJK up with her murderer:
Mary Kelly lost the key to her room. Joseph Barnett her ex-lover and she had had a violent quarrel and the window next the door ended up partly smashed on the 30th October. Without the key, she reached in through the hole in the glass to unlock the door to let herself in. This was stated in Joseph Barnett’s statement to the police which they accepted. But the door was found locked and the police had to break it down after her mutilated body was seen through the hole by the man collecting the rent.
It seems that the door locked automatically when it was closed and one had to reach through the window hole for the catch inside to open the door.
If she had the Ripper with her in her bed then he didn’t need to know how to open the door. If he crept in, he must have been familiar with her room. He must have observed how she opened the door at some stage.
Inspector Abberline speaking at the inquest said that the murderer did not lock the door behind him with the key. Nevertheless it is certain that the killer or somebody had a key and locked the room (page 64, The Complete Jack the Ripper). This must have been the situation because how else can the need to break the door down be explained? If the lock could be easily opened by putting one’s hand through the cracked pane as Barnett said then why did the police break the door in? The police must have looked to see if there was any way of entering the room without breaking the door in. You don’t do unnecessary damage at the scene of a crime. The police must have known if the door could really be opened by putting a hand through the window for working out how the murderer could have got in is an important part of the evidence. Possibly the police were acting unprofessionally but there is no reason to think this. The neighbours would have known how Kelly got into her room and could have told them. So there are reasons why the police thought that it couldn’t be done and so they didn’t try it. The suggestion that the police didn’t believe Barnett but decided later at the inquest that the door could be opened as he said is ridiculous.
The landlord didn’t even have a key either! So without a key they just broke in.
It seems that the police knew that Barnett wasn’t the killer and let him away with his lies. After all they had considered him a suspect in her murder. They wanted the whole investigation rushed through as if it was unnecessary. They acted as if they already knew who the Ripper was and there was no point.
Why did Barnett lie? Why did he want to protect the killer? Why did he act as if the police guessing that the Ripper had the key could lead them to the Ripper? The answer is that Barnett probably set up her meeting with the Ripper. Barnett worked at the Market and may have known our suspect who may have supplied meats to the Market.
If Joe Barnett was the Ripper or at least the killer of Mary Kelly it would have been a crime of passion for he lived a normal life after her murder. He wouldn’t lie beside her peacefully and then attack her. He did love the woman. He had no reason to go so far in the mutilations. He had no reason to make it look like the work of the Ripper – after all there were plenty of prostitute killers about.
Most likely the person who locked the door had to have been the killer. But what did the Ripper need the key for? He didn’t know then that Kelly was able to open the door by putting her hand through the broken glass. Was she really able to do this at all?
The missing key story was a lie. Kelly used the key and the Ripper locked the door with it and took it away with him after he desecrated her corpse. Did the killer take the key as a trophy similar to his stealing Annie Chapman’s rings?
The key was never lost. Kelly let herself and the Ripper in with it. The Ripper took the key with him. If as Barnett said, the key fell out of the lock when the door was slammed shut during a row it could have gone very far. She could have got a new key soon if it had been. And she wouldn’t have delayed if she was afraid of somebody like he said.
Barnett lied because he knew who had the key. In his stupidity he thought the lie was necessary to protect the killer. As if the police were going to search all the houses in Whitechapel for a tiny key! However, if the police had already suspected the killer his lie would have been far from stupid. This would tell us that one of the police suspects was the killer. The police would certainly search the houses of the suspects of the time. It would tell us too that the killer was a local resident. He was not the American quack doctor Francis Tumbelty. He was not Aaron Kosminski who nobody would have been afraid of especially another man. He was not D’Onston for Barnett wouldn’t have been that afraid of him. The killer had to have been a Jew and Barnett was afraid of the Jews who were protecting the killer. He had to live among them. The killer was not George Chapman for he was only 23 at the time of the killings while the witnesses saw an older man. And Chapman’s English wasn’t as good as the English of the Ripper. A police suspect Michael Ostrog was free to commit more murders after the Whitechapel murders stopped and didn’t while a maniac like the Ripper shouldn’t be able to stop. GWB the Australian suspect who according to his son admitted to the murders saying he had been getting very drunk and then getting the urge to gut prostitutes doesn’t sound very plausible. It doesn’t explain why the killings stopped so soon after starting. Its only hearsay.
"The key was never lost. Kelly let herself and the Ripper in with it. The Ripper took the key with him."
In which case it was an exercise in futility. The key was altogether redundant for ingress to her room.
The whole business with the key twists my melon. The point remains that if it was a simple case of putting your hand through the window and unlatching it, why did the police break the door down? Not unless, of course, as the article implies, Barnett was making up this story and the key had never been lost? I'm still curious as to why the Ripper felt the need to lock the door upon his exit (whether by key or the window trick).
Also, this article seems to favour Jacob Levy for the murders. He's a relatively new one to me but on first impressions I must say he certainly does appear to be a better suspect than most. Do you have any views on his candidacy?
My logic on why not sticking your hand through the window was because of the mutilated corpse inside the room. I can promise you that no matter what assurances I was given, I would not have been the person to slide my hand through that window to unlock the door. Maybe it was thought at the moment that the killer was still inside?
Or maybe the most simple explanation is, because they didn't know you could unlock it through the window and it was only after Barnett told them the trick that Abberline went back and tested it and verified that it was in fact, "very easy".
If the key was never lost, why keep a broken window? Especially the window pane needed to unlock the door. If you were fearful for your life it would seem logical that you would only leave easy access to your room if you absolutely had to because of a lost key.
I don't see anything that stands out as Barnett lying. I see the exact opposite actually. He seems a guy who is telling the truth even if it makes him look not in the best light.