This distinction could be quite significant when assessing the Bangladesh Police's theory of how four people were allegedly killed by two men, each 'high' on nine yaba tablets between them.

Yaba tablets are usually swallowed orally. In some settings, methamphetamine-containing tablets may also be crushed and inhaled or otherwise consumed, but the common route for intact yaba tablets is oral ingestion.

For the Rangpur case, if the police claim that the two accused consumed nine tablets between them, the important investigative question would be how that consumption was established-for example, whether witnesses saw them take the tablets, whether tablets were recovered, whether the tablets were chemically analysed, and whether toxicology testing of the accused subsequently detected methamphetamine. A statement about consumption alone is not a toxicological finding.

Methamphetamine toxicity is highly variable, and survival after such consumption is entirely possible.

What matters for the investigation is whether the tablets were chemically tested, whether biological samples were collected from the accused soon afterwards, and whether toxicology established the level of intoxication at the relevant time. In the absence of such evidence, the yaba claim remains an assertion rather than a forensic finding.

Two people can survive after collectively consuming nine yaba tablets; the number of tablets alone cannot establish that they would have died or even necessarily become incapacitated.

However, the more important point is that Bangladesh Police did not take any blood or urine samples of the two accused persons, Siddhartha Das and Mugdha Das, for toxicological examination that would determine the proportion of methamphetamine in the yaba tablets.

Yaba is commonly a tablet containing methamphetamine, often with other ingredients. Methamphetamine toxicity varies substantially with the actual amount of active drug, tablet composition, tolerance, body size, health, timing and whether other substances were consumed.

High doses can cause severe agitation, hyperthermia, seizures, cardiovascular collapse, stroke and death, but toxicity does not follow a simple "X tablets = fatal" rule.

If the allegation is that Siddhartha and Mugdha, accused as the alleged killers of the Chakrabory family from Daspara in Rangpur city, consumed nine yaba tablets between themselves and then proceeded to overpower and strangle four people, the important forensic question is not simply whether nine tablets can be survived. They plainly can be, in some circumstances.

The more relevant questions are:

The last point is particularly important. Methamphetamine intoxication can range from relatively mild or even minimally symptomatic presentation to severe toxicity involving agitation, psychosis, seizures and cardiovascular instability.

Therefore, the mere claim that the suspects consumed nine tablets does not establish their incapacity-or their capacity-to commit the murders.

There is also an evidentiary issue. If police are relying on the alleged yaba consumption as part of their explanation of the suspects' behaviour, toxicological testing would be far more probative than a statement that they consumed nine tablets.

The absence of contemporaneous blood/urine testing would leave an important part of that narrative unverified.