Mr Barr announced in a statement that the death penalty would be implemented in order to bring justice to the families of victims, and that the five death-row inmates have all been convicted of murder.
In some cases, the individuals have also been convicted of the torture or rape of children and the elderly.
Mark Mullins is from the campaign group Christian Watch and advocates for the death penalty.
Speaking to Premier he said he believes it is a biblical principle: "I believe scripturally it is justified."
"I support it because it's in Genesis chapter nine. At the same time that we were given the rainbow as a promise by God that he would not visit the same flood judgement on the nations of the world, he imposed a death penalty."
"The Law of proportionality - An eye for an eye, tooth for tooth, a life for life. And I believe that in justice and in other areas of the law we impose the lex talionis, proportionate punishment for the crime."
When asked how capital punishment can be justified within the Christian teachings of forgiveness and redemption he said that the state has been given the authority to take life by God and argued that many Christians would participate in a just war without any moral conflict.
"What is the difference between a just war where life is taken and imposing the death penalty when somebody is found guilty of taking another person's life deliberately? I suggest there isn't a difference.
He went on to say that the justice system safeguards individuals from taking personal justice into their own hands.
"The danger is if you remove the right of the state to take life, following the judicial process, what you're going to encourage is a shoot to kill policy.
The capital punishment debate resurfaced in the UK, following Boris Johnson's recent appointment of Priti Patel as home secretary - an MP who publicly advocated for the death penalty in 2011.
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