Fingerprinting with Ink

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Tips for rolling fingerprints

Clean the person’s hands with soap and water before applying the ink or scanning.
- If the hands are damp, wipe the fingers with rubbing alcohol.
- If the hands are dry or flaky, moisturize with a small amount of hand lotion and wipe off any excess.
Make sure the person is standing comfortably and their forearms are parallel with the floor.
Tell the person to look away, relax, and not try to help the rolling process.

With your right hand, hold the person’s right hand at the base of the thumb. Cup your hand over the person’s fingers and tuck under the fingers not being printed.
- Guide the finger being printed with your left hand.
Roll the finger on the ink to cover the whole fingerprint area. Ink should cover
- from one edge of the nail to the other.
- from the crease of the first joint to the tip of the finger.
Roll the inked finger on the card. Start from one edge of the finger and roll all the way to the other edge.
- Do not press down. The weight of the finger is enough pressure to record the print.
- Roll fingers away from the center of the body.
- Roll thumb toward the center of the body.
Lift the finger up after rolling to avoid smudging the print

Now that you have your prints, you need to try to identify them.

💡 Tip: Create a sheet with 4 columns and label: loop, whorl, arch, and individual features. Use this to record your observations.

Determine which of the three categories the print falls under—loop, whorl, or arch. This is the primary way of classifying a print, initially.
- loop = leans to the right or left
- whorl = swirling pattern
- arch = “hill” shaped
Identify the ridge characteristics in the print.
- Bifurcations or forks
- Bridges
- Dots
- Ending ridges
- Enclosures or islands
- Spurs or hooks
- Trifurcation
- Double bifurcation