Fingerprints

A person's fingerprints are commonly used by law enforcement to identify and capture suspects.

A lack of fingerprints along with other suspicious forensic evidence is occasionally a clue for Sam and Dean that they are dealing with something unnatural. Both of the Winchesters have been fingerprinted after being arrested with their fingerprints, at the time, linking Dean to over a dozen possible crimes. As a result, the Winchesters often make sure to wipe away their fingerprints at crime scenes to avoid being identified as having been there. A Nephilim's fingerprints are different than that of a regular human's being vertical lines rather than whorl. A ghoul can leave behind traceable fingerprints that can be matched up, at least while they are using one consistent form.

Episodes

1.14 Nightmare

After witnessing Roger Miller's murder, Dean orders Sam to remove his fingerprints to make sure that no one knows that they were ever there.

2.07 The Usual Suspects

After being arrested in Baltimore on suspicion of murder, Dean's fingerprints are noted to be all over the crime scene. Additionally, when the police run his fingerprints through the system, they come back with over a dozen possible hits connecting him to other crime scenes as stated by Detective Diana Ballard to Sam. Sam points out that they are only possible hits and Ballard wonders what they will get back if they run Sam's fingerprints.

2.14 Born Under a Bad Sign

After discovering footage of "Sam" murdering Steve Wandell, Dean orders him to wipe away his fingerprints to keep from being identified.

2.19 Folsom Prison Blues

As part of being booked into jail, both of the Winchesters are fingerprinted.

3.15 Time Is on My Side

While meeting with Rufus Turner, Dean asks if he ran Bela Talbot's fingerprints. Rufus admits that he tried, but had failed as Bela long ago burned her fingerprints off. Instead, Rufus was able to identify Bela by taking a picture of her ear from his security camera and running that instead.

7.14 Plucky Pennywhistle's Magical Menagerie

After being confronted by the Winchesters in their guise as FBI agents, a nervous Cliff asks them if they are there to talk to him about the meth lab that got "fireballed." Cliff claims that it wasn't him but his brother who has the same fingerprints.

8.08 Hunteri Heroici

While telling the Winchesters and Castiel about the "Black Hole" robber, Detective Glass states that he is a real pro who leaves no fingerprints behind.

8.16 Remember the Titans

After Prometheus is killed by a grizzly bear, an attempt is made to identify him with his fingerprints to no avail. After Dean suggests that he could have a shady past, Sam points out that guys with shady pasts usually have their fingerprints on file.

10.15 The Things They Carried

While investigating the murders committed by Rick Willis while under the influence of a khan worm, the Winchesters learn from the local sheriff that Willis' fingerprints were all over the crime scene along with his dog tags being found right by the body.

11.07 Plush

After calling in Sam and Dean to help with a killer in a bunny mask, Sheriff Donna Hanscum tells them that they ran the man's fingerprints but they are not in the system.

13.01 Lost and Found

After running Jack Kline's fingerprints, Sheriff Christine Barker is shocked to see how different they look to a regular human's.

13.06 Tombstone

After meeting up with Dean outside of the local funeral home, Sergeant Joe Phillips tells Dean that along with the bank teller identifying Dave Mather as the culprit by voice, his fingerprints from the bank robbery matched the fingerprints found at the scene of his nephew's murder.