why would would he need to do that.
Why had/would Bamber burn Nevill's back ? Lots of reasons -
The concensus from both sides is they were burn marks.
Bamber had put Nevill onto a coal scuttle where his bare back was easily available.
Nevill was immobilised. He would not fight back from the burns.
The aga was next to Nevill.
There were rifles available to heat & use.
Bamber wanted to make sure Nevill was dead for several reasons.
Bamber was composed & calculated enough to calm down after the kitchen fight to do burn Nevill's back.
Bamber had time to burn Nevill's back.
Bamber had to ensure Nevill was dead as Nevill would incriminate him if he survived.
Bamber may have considered this option beforehand if he felt he had to check for life.
If this was considered beforehand by Bamber, he could have brought his own burning item.
The rifle nozzle would take several minutes to heat sufficiently, Bamber could attend to other framing business.
The rifle nozzle would not be damaged after being burnt.
The evidence is Bamber took off the silencer after shooting Sheila. So had the rifle nozzle available to burn Nevill's back. Although as said other rifles were available.
There are no other credible alternative explanations why Nevill would have what experts say are three recent burn marks on his back which are the same size as rifle nozzles.
Burning Nevill's back is an effective way to check for life. A partially concious Nevill would certainly react.
Nevill was only shot 4 times upstairs. Bamber may have burnt Nevill's back prior to or while shooting him again downstairs. Bamber would not have known how many more shots were needed at Nevill after the kitchen fight. Burning his back after 1-4 shots is a way to check for life.
There is no reason why Sheila would burn Nevill's back.
It was impossible for Sheila to lift Nevill.
Sheila did not have the time to burn Nevill's back.