Rejected petition Bring Back Capital Punishment

The last executions in the United Kingdom, by hanging, took place in 1964, prior to capital punishment being abolished for murder (in 1965 in Great Britain and in 1973 in Northern Ireland). Although not applied since, the death penalty was abolished in all circumstances in 1998.
What I would like to know is whether it would be possible to consider bringing back the death penalty for murder. Too many criminals nowadays are aware that if they commit any crime, whether it be theft or killing another human being, the worst case scenario they will face is a life in prison with meals, warmth, clothing, gym and shelter which is paid for by us, the taxpayer, which I find disgraceful.
These criminals who even think of killing another person would maybe think twice about acting upon it if they knew they could lose their own life.
There isn't any other way to reduce murders as they know if they get caught and imprisoned they have an easy life behind bars.