March 11, 2004: Terrorists detonate bombs on a number of trains in Madrid, Spain, killing approximately 191 people, and injuring thousands more, including a number of United States citizens.

May 6, 2004: Brandon Bieri Mayfield, a 37-year-old civil and immigration lawyer, practicing in Portland, Oregon, is arrested as a material witness with respect to a federal grand jury’s investigation into that bombing. An affidavit signed by FBI Special Agent Richard K. Werder, submitted in support of the government’s application for the material witness arrest warrant, [avers] that Mayfield’s fingerprint has been found on a bag in Spain containing detonation devices similar to those used in the bombings, and that he has to be detained so that he cannot flee before the grand jury has a chance to obtain his testimony.

May 24, 2004: The government announces that the FBI has erred in its identification of Mayfield and moves to dismiss the material witness proceeding.75

In March 2006, the Office of the Inspector General of the U.S. Department of Justice issued a comprehensive analysis of how the misidentification occurred.76 And in November 2006, the federal government agreed to pay Mayfield $2 million for his wrongful jailing in connection with the 2004 terrorist bombings in Madrid.77 The Mayfield case and the resulting report from the Inspector General surely signal caution against simple, and unverified, assumptions about the reliability of fingerprint evidence.

In Maryland v. Rose, a Maryland State trial court judge found that the Analysis, Comparison, Evaluation, and Verification (ACE-V) process (see Chapter 5) of latent print identification does not rest on a reliable factual foundation.78 The opinion went into considerable detail about the lack of error rates, lack of research, and potential for bias. The judge ruled that the State could not offer testimony that any latent fingerprint matched the prints of the defendant. The judge also noted that, because the case involved


S.T. Wax and C.J. Schatz. 2004. A multitude of errors: The Brandon Mayfield case. The Champion. September-October, p. 6. The facts of the case and Mayfield’s legal claims against the government are fully reported in Mayfield v. United States, 504 F. Supp. 2d 1023 (D. Or. 2007).


Office of the Inspector General, Oversight and Review Division, U.S. Department of Justice. 2006. A Review of the FBI’s Handling of the Brandon Mayfield Case. Available at


E. Lichtblau. 2006. “U.S. Will Pay $2 Million To Lawyer Wrongly Jailed.” New York Times. November 30, at A18.


Maryland v. Rose, Case No. K06-0545, mem. op. at 31 (Balt. County Cir. Ct. Oct. 19, 2007) (holding that the ACE-V methodology of latent fingerprint identification was “a subjective, untested, unverifiable identification procedure that purports to be infallible” and therefore ruling that fingerprint evidence was inadmissible). The ACE-V process is described in Chapter 5.

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement