BUDDING crime-scene investigators take note: a common household bleach can render the forensic techniques for detecting blood useless.
There are two types of bleach found in household cleaning products. Chlorine-based bleaches are known to make bloodstains invisible, but applying chemicals such as luminol or phenolphthalein will still reveal the presence of haemoglobin – crucial for identifying blood – even after up to 10 washes. In contrast, oxygen bleach, which contains an oxidising agent such as hydrogen peroxide, erases all trace of haemoglobin. Its effect seems to have been untested until now.
Fernando Verdú and his team at the University of Valencia, Spain,…
