- "Marty turned the corner into the alley and stopped. / Jennifer was still there, asleep, where Doc had left her. / But she was no longer alone. Two women cops were getting out of their police car. They strolled over to where Jennifer was curled up, snoring peacefully. / 'Tranked out, I'd say,' one of the cops ventured. 'Smell her ears.' / The other cop obliged with a frown, but shook her head. 'Nothing.' / 'Run a thumb check,' the first one ordered. / The second cop lifted Jennifer's arm, then pressed the sleeping girl's thumb against the side of a small silver box. / A flat, machine voice spoke from the box, clearly but rapidly: / 'Name: McFly, Jennifer Jane Parker. Address: 3793 Oakhurst Street, Hilldale. Date of birth: October 29, 1968. Arrests: none. Warrants: none. Convictions: none.' "
- —From Back to the Future Part II by Craig Shaw Gardner (quote, page 53)
The subject's thumb would be pressed against a pad on the device, and their details read aloud in the following order: 'Name', 'Address' and 'Date of Birth'.
Officers Reese and Foley of Unit N11-11 used an identa-pad to identify the tranquilized Jennifer Parker of 1985, having found her in an alleyway. Having concluded that she was the Jennifer of 2015, they took her home to the McFly residence in Hilldale.
Behind the scenes
- The identa-pad is never referred to by name, either in the movie or in the novelization, and is never seen in detail on-screen, so it remains unclear as to whether the device had a screen on which the subject's details were also displayed. In the movie, the term 'thumb check' is used by the officers, but this is more likely a reference to the procedure rather than to the identa-pad itself.
- The name 'identa-pad' is used for the first and only time in a full colour design drawing of a 2015 Hill Valley Police duty belt, which appears on page 73 of Back to the Future: The Official Book of the Complete Movie Trilogy, with the accompanying caption "Standard issue for the officers of the Hill Valley Police Department." The drawing also points out other equipment on the belt: 'mini-strobes'; 'taser and flash-light'; 'nightstick'; and 'storage and power unit'.
- In the novelization (see Quote above), as well as giving Jennifer's 'Name', 'Address' and 'Date of Birth', the identa-pad also details 'Arrests', 'Warrants' and 'Convictions' — which are "none" in each case.
- Portable fingerprint scanners comparable to the identa-pad exist, and are in widespread use by police in the UK for identification of suspects. 
- Use of biometrics for identification and security is increasingly common — for example, biometric passports are already in use, fingerprint scanners are used at such locations as airports, and fingerprints are also used to unlock smartphones and/or laptop computers.
- Back to the Future Part II
- Back to the Future: The Official Book of the Complete Movie Trilogy (First identified as 'identa-pad')
- Back to the Future Part II novelization