Erratum to: Reliability and Validity of Prisoner Self-Reports Gathered Using the Life Event Calendar Method

Data collection using the life event calendar method is growing, but reliability is not well established. We examine test–retest reliability of monthly self-reports of criminal behavior collected using a life event calendar from a random sample of minimum and medium security prisoners. Tabular analysis indicates substantial agreement between self-reports of drug dealing, property, and violent crime during a baseline interview (test) and a follow-up (retest) approximately 3 weeks later. Hierarchical analysis reveals that criminal activity reported during the initial test is strongly associated with responses given in the retest, and that the relationship varies only by the lag in days between the initial interview and the retest. Analysis of validity reveals that self-reported incarceration history is strongly predictive of official incarceration history although we were unable to address whether subjects could correctly identify the months they were incarcerated. African Americans and older subjects provide more valid responses but in practical terms the differences in validity are not large.     

Vulnerabilities of fingerprint reader to fake fingerprints attacks

The purpose of this research is to assess the vulnerabilities of a high resolution fingerprint sensor when confronted with fake fingerprints. The study has not been focused on the decision outcome of the biometric device, but essentially on the scores obtained following the comparison between a query (genuine or fake) and a template using an AFIS system. To do this, fake fingerprints of 12 subjects have been produced with and without their cooperation. These fake fingerprints have been used alongside with real fingers. The study led to three major observations: First, genuine fingerprints produced scores higher than fake fingers (translating a closer proximity) and this tendency is observed considering each subject separately. Second, scores are however not sufficient as a single measure to differentiate these samples (fake from genuine) given the variation due to the donors themselves. That explains why fingerprint readers without vitality detection can be fooled. Third, production methods and subjects greatly influence the scores obtained for fake fingerprints.