Most people, when they go to the Old Bailey Online look for a name, a place, or perhaps a crime.

As the largest collection of transcribed trial accounts on the web, the site is used by thousands of family and local historians searching for lost black sheep, and local villains.

It has also been mined for dramatic stories of fear and loathing, redemption and despair, and has formed the grist of dramas such as Garrow's Law. Australians looking for convict ancestors, dramatists keen to find a narrative arc in the tragedy of crime and punishment; and academic historians searching for the perfect illustrative anecdote, all visit the site in their thousands every day.

Amanda Vickery's new series of Voices from the Old Bailey, which started on BBC Radio 4 this week, forms a new and different way of making these courtroom tragedies speak to a modern audience. And what they are all looking for is the connection to the past that only comes with detail and emotion.

Family historians, for instance, all want a name and an occupation, an age and a physical description, but more than this they want to hear in recorded testimony the voice of an ancestor. And sometimes a single word is worth a thousand pictures.

Radio 4 listeners can explore the darker sides of their family trees by searching for criminal forebears too. If your surname was Burt, for example, you might search simply for the name "Burt" and find Samuel Burt, convicted of forgery. Modern day Burts can read their ancestor's eloquent plea to the court - he was an effective orator, but ended up being transported on the first fleet to Australia.

When I search the old Bailey's 127 million words, I always look for just those few expressions that cross the centuries.

I look for emotions, and when I find them, it seems as if all the fancy dress, and generations of difference immediately fall away in the face a simple feeling. When we were looking for trials that could bring the Old Bailey Proceedings to life on air that was my strategy. I searched for particular kinds of words and phrases: frightened, terror, 'out of my wits', 'shaking with fear', and what came up again and again, were trials in which the harrowing emotional experience of a single crime are described by the people who suffered it.

'Out of my wits', for instance, brings up 25 trials. In the end, we did not use any of these trials in the broadcasts, but among them was the trial of five men for assaulting William Wilson on Salt Petre Bank late one night in 1781. Knives were pulled and the threat was made to 'let his puddings out' - and leave him to die. That phrase, 'let his puddings out' even now makes me tense my stomach just a bit with anxiety. And in its turn 'puddings out', leads to two other trials in which a phrase drawn from butchery, was applied to first a man and then a woman. Word by word, emotion by emotion, and just as easily starting from an ancestor or a place as from a single word, the Old Bailey Online makes it possible to trace a line of continuity through the records from the seventeenth century to the twentieth.

I always say of the Proceedings, that all human life is there. And it is true that lords and beggars, shoemakers and laundresses can all be found among the thieves and their victims, but what I really mean is that every sensation from fear to joy, from pleasure to pain, everything that ties us directly to our predecessors and makes us part of 'human life' is there.

If you're inspired to delve into this criminal archive, start here at the Old Bailey Online homepage. The site includes a video tutorial, Getting Started, to help you navigate this rich source of archive, and a Guide to Searching.

Professor Tim Hitchcock is co-director of Old Bailey Online; London Lives and Connected Histories