We encourage our witness to make sketches as soon as possible after their sightings – before they contact us, and certainly before they discuss any details with other witnesses. This is true regardless of whether there are photos or videos. Now, some new research at University of Waterloo in Canada lends some scientific support to this practice. They found that drawing is superior to other memory retention techniques. So, not only does making a sketch help us understand what witnesses saw, it helps the witnesses retain their memory better.
We hope this will be followed up by more research that will help us understand in more detail how the sketch reinforces or affects witness memories.