Skip to ContentGo to accessibility pageKeyboard shortcuts menu
OpenStax Logo

A photo of a smiling man with gray hair, with a microphone attached to his tie.
Figure 14.1 Michael Morton went to jail in 1986 for the murder of this wife. Twenty-five years later, in 2011, he was exonerated of her murder by DNA evidence. (credit: Lauren Gerson)

Each person’s DNA is unique, and it is possible to detect differences among individuals within a species on the basis of these unique features. DNA analysis has many practical applications, including identifying criminals (forensics), determining paternity, tracing genealogy, identifying pathogens, researching archeological finds, tracing disease outbreaks, and studying human migration patterns. In the medical field, DNA is used in diagnostics, new vaccine development, and cancer therapy. It is often possible to determine predisposition to diseases by sequencing genes.

Sometimes an innocent person is erroneously convicted of a crime and sent to jail. Between 2000 and 2015, evidence from DNA was used to exonerate over 250 innocent people. Twenty of those people were on death row after being convicted of a murder they didn’t commit. To learn more about the intense scientific and legal processes used to exonerate those wrongfully convicted, go to The Innocence Project website here.

Teacher Support

Determination of DNA patterns has many uses. In criminal proceedings, DNA analysis has become almost routine and many juries depend on it. However, DNA samples for analysis may not be available in all cases, or DNA might be contaminated. Occasionally, DNA preserved from a crime committed before DNA analysis was available is used as evidence at a retrial.

Order a print copy

As an Amazon Associate we earn from qualifying purchases.


This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute OpenStax.

Attribution information
  • If you are redistributing all or part of this book in a print format, then you must include on every physical page the following attribution:
    Access for free at
  • If you are redistributing all or part of this book in a digital format, then you must include on every digital page view the following attribution:
    Access for free at
Citation information

© Apr 26, 2024 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.