A brilliant cross-examination that gets an innocent person off the hook or puts a guilty one behind bars is a staple of courtroom dramas and novels. A study by researchers at the universities of Liverpool and Leeds shows that schooling witnesses in the kind of questioning techniques used by lawyers can actually help improve the accuracy of their answers. The researchers showed more than 50 participants footage of a staged crime and then subjected them to the kind of questioning techniques that they might come across in court. They found that the participants who had been given prior guidance on cross examination techniques were able to respond appropriately and were less likely to make mistakes. The researchers thought that the use of complex questions containing multiple parts, double negatives and advanced vocabulary employed by lawyers taxes the brain making it less able to filter and organise information. By preparing the participants in advance they were able to devote less energy to understanding the lawyer and more to answering the question.