South Carolina lawmakers vote to allow execution by firing squad

South Carolina state lawmakers have voted to allow firing squads to be implemented as a method of capital punishment in the state.

The Republican governor, Henry McMaster, has said he will approve the bill when it arrives at his desk, making South Carolina only the fourth state in the US that allows death by firing squad. Mississippi, Oklahoma and Utah already allow the execution method, according to the non-profit Death Penalty Information Center.

Related: Nevada death row inmate asks to be killed by firing squad

A shortage of lethal injection drugs and its effect on South Carolina’s ability to implement capital punishment was cited as the reason for the decision. As the death penalty continues to be subject to widespread criticism, many drug companies have decided to stop selling the drugs to states.

A Democratic representative, Justin Bamberg, spoke to colleagues before the vote, urging them to reject the bill.

He said: “If you push the green button at the end of the day and vote to pass this bill out of this body, you may as well be throwing the switch yourself.”

South Carolina’s supply of life-ending drugs expired in 2013, and the state has not gone forward with a prisoner execution since 2011. Currently there are 37 people on the state’s death row who have exhausted the appeal process.

Prisoners who have been sentenced to death have all chosen lethal injection in recent years.

If McMaster signs the bill into law, those prisoners will again be in line for the death penalty, with the state being required to execute them by electrocution or gunfire if lethal injection drugs are not available. Only nine states currently allow use of the electric chair.

South Carolina first began using the electric chair in 1912 after taking over implementation of the death penalty from individual counties, which usually hanged prisoners. Only three inmates, all in Utah, have been killed by firing squad since 1977. Nineteen inmates have died in the electric chair this century.

The bill was approved by a 66-43 vote. It was already approved by the state senate in March by a vote of 32-11, but given minor technical changes before its approval this week.

Democratic lawmakers attempted to amend the bill with details that would increase pressure on the state to provide transparency in its executions. Some of the amendments, which all failed, included live-streaming executions on the internet, and mandating that lawmakers watch the executions as they happen.

Lawsuits are expected to delay any immediate executions following the signing of the law.