US execution delayed after failed lethal injection

The execution of Idaho's longest-serving death row inmate has been delayed after officials failed to deliver a fatal lethal injection dose.

The death sentence against serial killer Thomas Creech, 73, was due to be carried out in Boise on Wednesday.

"The medical team could not establish an IV line, rendering the execution unable to proceed," prison officials said in a statement.

The execution would have been Idaho's first in 12 years.

Creech has been in prison since 1974 and was sentenced to die for the 1981 fatal beating of a fellow inmate. He is one of the US's oldest death row inmates.

He has been convicted of five murders in three states, and is suspected of several other killings. Just last month, authorities near Los Angeles closed a nearly 50-year old murder case after successfully identifying Creech as the suspect.

Wednesday's execution was due to occur hours after the US Supreme Court denied multiple requests from his legal team to stay the sentence, after finding no grounds to merit any leniency.

Idaho Department of Correction spokesperson Sanda Kuzeta-Cerimagic told reporters that the inability to establish an IV line meant that the state's death warrant would expire, leaving it to "consider next steps".

Creech's lawyers said in a statement that the state tried to access his veins in both of his arms and legs 10 times before giving up.

"We are angered but not surprised that the State of Idaho botched the execution of Thomas Creech today. This is what happens when unknown individuals with unknown training are assigned to carry out an execution," they said in a statement.

The identifies of individuals who perform executions in the US are protected by the state.

The botched lethal injection is the latest example of a state struggling to perform the fatal procedure. Alabama was forced to call off two lethal injection executions in 2022 after failing to successfully locate the inmates' veins.

One of the two Alabama inmates was put to death last month, with a new previously untested method of using nitrogen gas to cut off oxygen to the brain.

Last year, lawmakers in Idaho passed a law authorising inmates to be executed by firing squad.

However, officials have yet to construct a facility where those executions would occur, as well as write a policy regarding how they are carried out, according to the Associated Press news agency.

Idaho's botched procedure came hours before Texas was due to execute a double murderer who continues to profess his innocence.

Ivan Cantu and his supporters argue that he deserves a retrial due to ineffective defence counsel during his trial.