An unidentified decedent, or unidentified person (also called UID or UP), is a body whose identity cannot be found by police or medical examiners. In some cases, it takes many years to learn who the person was, and in other cases, the person is never identified. A UID may remain unknown because there is not enough evidence or because the person did not have personal identification, such as a driver's license. If the body is too damaged or broken down to be easily recognized, the face of a UID may be rebuilt to show what they looked like before death. In countries where English is spoken, UIDs are often given temporary names like "John Doe" or "Jane Doe."

Causes

As of 2023, there were about 14,000 unidentified individuals in the United States. A body might not be identified if the person was not recorded in the state where they died, if their body is highly decomposed, or if they have severe facial injuries. In the United States, teenagers who ran away from home might be removed from missing person lists when they turn 18, which can make it harder to match them with unidentified remains. Between 1964 and 2015, the Ontario Provincial Police database recorded 371 unidentified people.

Some unidentified individuals died in states other than where they were born. For example, the Sumter County Does, who were murdered in South Carolina, were initially believed to be Canadian but were later identified as people from Pennsylvania and Minnesota. Barbara Hess Precht died in Ohio in 2006 but was not identified until 2014. She had lived in California with her husband for many years before returning to Ohio, where she died under unknown circumstances. In both of these cases, the bodies were found in a condition that made it easy to take fingerprints and dental records. It is unclear if DNA from the Sumter County Does was recovered, as their bodies would need to be dug up for DNA testing. Many undocumented immigrants who die in the United States after crossing the border from Mexico remain unidentified.

Some unidentified individuals are found long after their death and are severely decomposed, which can change their facial features and make identification difficult through fingerprints. Environmental conditions greatly affect decomposition. For example, some bodies may remain nearly unchanged if found in cold areas months after death, while others in warm areas may decompose quickly or even become mummies. One example is the "Persian Princess," who died in the 1990s but was falsely claimed in Pakistan to be over 2,000 years old in an act of archaeological forgery.

Putrefaction occurs when bacteria break down remains and produce gases that cause the body to swell and change color. In the case of the Rogers family, who were murdered in 1989 by Oba Chandler, their bodies were placed in water and later floated to the surface due to gases inside them. They had died shortly before being found but were already severely decomposed and unrecognizable because of putrefaction and high temperatures. Their identities were discovered a week later through dental records.

Skeletonization happens when a body decays so much that only bones and a few tissues remain, usually after a long time since death. If a skeletonized body is found, fingerprints and toeprints may not be recoverable unless they survived the early stages of decay. Fingerprints were once widely used to identify the dead before DNA testing became common. In some cases, partial remains make identification difficult. If dental records and DNA databases do not help, forensic reconstruction may be used to identify skeletonized unidentified individuals.

Sometimes, people who try to hide a body may destroy it or make it unrecognizable. Mario Zunigarobles was killed about an hour before his body was found, but he was completely unrecognizable. When Canadian model Lynn Breeden was murdered and set on fire in a dumpster, her body was so badly damaged that DNA and fingerprint analysis were not possible. She was later identified when her unique teeth matched her dental records, and DNA from her blood found at a different location was matched. Linda Agostini’s body was found burned near Albury, Australia, in 1934. Her remains were identified ten years later through dental records.

Identification process

Bodies are usually identified by comparing their unique DNA, fingerprints, and dental features. DNA is the most accurate method, but it was not widely used until the 1990s. It can be collected from hair follicles, blood, tissue, and other biological materials. Other physical clues, such as illnesses, signs of surgery, broken bones, and height and weight, can also help identify a body. A medical examiner often helps with this process. Since 2018, genetic genealogy has been used to match the DNA of the deceased with that of relatives who have shared their DNA on genealogy websites.

Many police departments and medical examiners try to identify the deceased by posting mortuary photographs of the unidentified person’s (UID) face online. Sometimes, these photos are retouched to hide wounds before being shared with the public. Dismembered bodies may also be digitally altered to look whole. This method is not always effective because the face of an UID may be distorted by the way they died. For example, "Grateful Doe," who died in a car crash in 1995, had severe injuries that changed the shape of his face.

A Jane Doe found in a river in Milwaukee, Wisconsin, had died months earlier but was preserved due to cold temperatures. Her morgue photographs were posted online, but her face had swollen and was distorted from absorbing water and decomposing.

Death masks have also been used to help identify bodies. These masks are made to show a relaxed expression, which may not match the appearance of the UID when they were found. For example, "L'Inconnue de la Seine," a French woman who died by suicide in the late 1800s, had a death mask that did not reflect how she looked in life. However, death masks can still show signs of long-term illnesses, such as sunken eyes.

When a body is found in a highly decomposed state or died violently, reconstructions may be needed to help the public identify the person. This is often done when showing photos of a corpse is considered inappropriate. Faces can be reconstructed using 3D models or 2D methods like sketches or digital images. Sketches have been used in many cases. In the 1980s, forensic artist Karen T. Taylor developed a method to create more accurate sketches by estimating the size and position of facial features on a skull. This method has worked well in some cases.

The National Center for Missing and Exploited Children has created a method to estimate the faces of UIDs whose remains are too damaged for traditional sketches. A skull is scanned using a CT machine, and software originally designed for architecture is used to add layers of tissue based on the UID’s age, sex, and race.

Examples of how UIDs have been reconstructed include:
• Death mask (L'inconnue de la Seine)
• Forensic sketch (Broward County John Doe, 1979)
• Facial composite (Pinellas County John Doe, 1980)
• Three-dimensional clay reconstruction (Caroline County John Doe, older decedent)
• Jane Doe alias “Mary Anderson”
• Reconstruction using a CT scan (Lumberton Jane Doe)

In some cases, law enforcement made mistakes in identifying UIDs. For example, Colleen Orsborn had a broken leg bone, but the medical examiner who examined her remains missed this injury and ruled her out as a suspect. DNA testing in 2011 confirmed she was the victim found in 1984. Similarly, in the case of Racine County Jane Doe, later identified as Peggy Johnson-Schroeder, the exclusion of a possible identity was criticized. Aundria Bowman, a teenager who disappeared in 1989, was not considered a match for a body found in 1999, even though she looked similar. This decision was later questioned on an online forum called Websleuths. In the case of Lavender Doe, later identified as Dana Dodd, a mother of a missing girl disagreed with the exclusion of her daughter based on DNA, as the reconstruction of the victim looked similar to her daughter.

Notable cases

• Whitehall Mystery, England, unknown since 1888
• Oak Grove Jane Doe, United States, unknown since 1946
• The Somerton Man, Australia, unknown since 1948, possibly identified in 2022
• Isdal Woman, Norway, unknown since 1970
• Fred the Head, United Kingdom, unknown since 1971
• Long Beach Jane Doe, United States, unknown since 1974
• Heul Girl, Netherlands, unknown since 1976
• Eklutna Annie, United States, unknown since 1980
• St. Louis Jane Doe, United States, unknown since 1983
• Vernon County Jane Doe, United States, unknown since 1984
• Nevada City Jane Doe, United States, unknown since 1984
• Teteringen Girl, Netherlands, unknown since 1990
• The Gentleman of Heligoland, Germany, unknown since 1994
• Jennifer Fairgate, Norway, unknown since 1995
• Persian Princess, Pakistan, unknown since 1996
• Mary Anderson, United States, unknown since 1996
• "Adam," United Kingdom, unknown since 2001
• "Girl from the Main," Germany, unknown since 2001
• Wembley Point Woman, United Kingdom, unknown since 2004
• Peter Bergmann, Ireland, unknown since 2009
• Angel of the Meadow, United Kingdom, unknown since 2010
• Smurfette Jane Doe, United States, unknown since 2012
• Clocaenog Forest Man, United Kingdom, unknown since 2015