|Cell phone screen to compare prints|
US Customs and Border Protection, Federal
When you have an identification document that shows a fingerprint or thumbprint and are unsure of if the carrier of the doc is an imposter, use the flat smooth screen of your cell phone to take their print. Have the subject rub their digit on their forehead and then roll or press onto your cell screen. By moving the cell phone to reflect a light source, you can see their print and compare the details of the loops arches and whorls. The phone's screen cleans easily enough, and you can make your ID determination in the field.