Reasons why Bamber didn't hire a hit man:
It would be very expensive. It was killing five people.
He would not have the contacts to find one.
Hit men have some morals, either killing other criminals, or the top hit men killing political people. A request to kill innocent men, women and children so Bamber can inherit may be refused by a hit man.
A hit man would want a big up front payment.
A hit man may take an up front payment and then disappear.
Bamber would have to find the money to make an up front payment, discreetly.
Bamber would have arranged for an alibi to prove he was not at WHF all night.
Bamber would have arranged for the hit man to telephone him, which his alibi would also hear.
Hiring a hit man takes total control away from Bamber. He is now reliant on another person.
A hit man could keep demanding more money to keep quiet.
Everything a hit man would do, Bamber had access to do himself and was capable of doing himself.
A hit man may pull out if things got difficult mid massacre. Such as when Neville got out of bed. The hit man has already been part paid and would not be as motivated as Bamber.
A hit man may refuse point blank Bamber's offer. Bamber is now aware that someone else knows/knew about his plans, pre or post massacre.
A hit man who is restrained by Neville, June and Sheila will implement Bamber.
Bamber didn't inherit, so didn't pay the alleged hit man. However the hit man has not contacted the police anonymously, and implicated Bamber as revenge.
Bamber would have to engage with other people when investigating where to find a hit man. This could be reported to the police.
If Bamber had the courage to pay for a hit man to have his family killed, he would have the courage to do it himself.
Bamber was only three miles from WHF and could get there without being seen.
If not going to arrange an alibi to stay with him at his cottage, and get the hit man to phone him, he would have made sure he was miles away, with witnesses. Perhaps in London where he often spent time.
Bamber knew how to use the murder weapon, so did not need to hire an expert.
Bamber was fit and strong enough to carry out the massacre himself.
If Bamber did arrange for himself to be miles away, that would create suspision. It was harvest time which was the busiest time of the year.
A hit man may make mistakes in creating the post massacre frame.
A hit man may get restless if not quickly paid after the massacre. Bamber may become the target. If the hit man can kill five people, then he would not hesitate with Bamber.
A hit man could easily implicate Bamber without implicating himself. By simply writing to the police anonymously.
A delay in payment post massacre, will mean the hit man may decide to implicate Bamber.
A hit man would know that his post massacre payment was reliant on Bamber's inheritance. This could take months or years. Or may never happen. So the hit man may refuse or request 100% payment up front.
The hit man may be arrested for another crime in the future. He may decide to make a deal with the police for a lesser sentence, and admit to previous crimes.
Hit men usually just fire a bullet, from a distance. To kill one person. This job was expecting the hit man to force entry to a house with five people inside , kill them all and arrange a frame. A massive departure from the norm. Many hit men would refuse to do this.
A hit man will want lots of notice and time to plan his hit. However Bamber would have only got short notice of Sheila's visit. Sheila was also only staying for a short period.
There are no advantages in Bamber hiring a hit man, and then not giving himself an alibi.
The evidence shows he did not hire a hit man.
