‘Truth Serum’ explained after Australian legal professionals argue for it to be used on murderers

The use of ‘truth serum’ is being controversially pushed by Australian legal professionals. Here’s how it works and its pitfalls.

A so-called ‘Truth Serum’ has been an instrumental tool in many a spy-film, but the drug on which it’s based – Sodium Pentothal or Sodium Thiopental – is now being pushed as a viable option for the Australian Government to compel criminals to reveal the whereabouts of dead bodies.

Former NSW crown prosecutor Margaret Cunneen SC and Victorian barrister Sharon Kermath said governments should force the serum on convicted murderers.

But others in the profession strongly oppose the suggestion, likening the drug to “torture” that strips criminals of fundamental rights and freedoms.

While its effectiveness and safety has also come into question, Ms Cunneen and Ms Kermath say the chemical should at least be trialled.

Here is a breakdown of what it is, how it works and issues surrounding its efficacy.

Barrister Margaret Cunneen has called for the use of ‘truth serum’ to force convicted murderers to reveal the location of victims.

WHAT IS TRUTH SERUM MADE OF?

Sodium Thiopental, also known as Sodium Pentothal, is a rapid-onset, short-acting barbiturate, once commonly used as a general anaesthetic and listed as a World Health Organisation Essential Medicine. Propofol took over as the preferred drug for anaesthesia, due to Sodium Pentothal being used as part of the cocktail of drugs used for lethal injections in the United States.

HOW DOES TRUTH SERUM WORK?

Barbiturates act on the central nervous system, depressing it to calm anxiety, induce drowsiness, eliminate pain, and in high enough doses, knock someone out. It’s during the middle phase, when the drug decreases both the higher cortical brain function as well as inhibitions, that it may act as a potential truth serum. The effect of the drug is thought to weaken the resolve of the user, making them more likely to tell the truth when probed.

Sodium Pentothal has previously been used as part of a cocktail of drugs for lethal injections. Picture: Supplied.

WHERE IS TRUTH SERUM CURRENTLY USED?

Due to its association with capital punishment, Sodium Pentothal has been marred by controversy. Furthermore, the use of the drug to compel truth-telling in a criminal context hasn’t been accepted in Western countries due to the perceived violation of basic human rights, including the right to remain silent.

Sodium Pentothal has reportedly been used as an interrogation tool in India, most famously in the case of Ajmal Kasab, the only surviving terrorist in the 2008 Mumbai attacks.

In 1967, Perry Russo, a key witness in the investigation into John F Kennedy’ assassination, was reportedly given Sodium Pentothal before his interrogation by District Attorney Jim Garrison.

According to Policing Academic Associate Professor Michael Kennedy, the drug is not currently used anywhere in the world as an investigative tool for criminal investigation.

“(More modern truth serums may be) used by intelligence agencies, likely CIA, Mossad and its Russian and Chinese counterparts, but not for criminal investigations, nor as a reliable evidence gathering tool.”

Associate Professor Michael Kennedy says ‘truth serum’ is unsafe and unreliable. Picture: Supplied

DOES TRUTH SERUM REALLY WORK?

Its reliability is up for debate. The theory is that during an uninhibited state, the user is less likely to lie, because doing so requires more effort.

But according to Associate Prof Kennedy, it “completely relaxes people to the point that, theoretically, they may not lie”, he stressed, it’s just a theory.

“Practically it is unreliable and very dangerous,” Associate Prof Kennedy said.

IS TRUTH SERUM SAFE?

Associate Prof Kennedy said Sodium Pentothal has the potential to create serious health problems, including both physical and mental conditions.

“It is about as safe and effective as water boarding,” he said.

“Its use is highly unethical, in breach of universal human rights agreements and totally at odds with post WW2 investigation techniques.”