Risk and rehabilitation in criminal records checking by employers: What employers are doing and why?

The use of criminal record checking has dramatically increased over the last 10-15 years, leading to concerns that ex-offenders are disadvantaged in seeking employment and therefore at greater risk of engaging in reoffending. In order to better understand why and how employers are using criminal record checks, a two-stage empirical research project was conducted involving a survey of and interviews with HR managers across a wide variety of industries. As indicated, a number of disadvantages to the wholesale use of criminal record checking in employment have been identified previously, such as obstructing the reintegration of ex-offenders and encouraging recidivism, limiting the labour pool, and exposing the organisation to discrimination claims and to the overreliance on a single type of risk assessment. This research, therefore, seeks to understand how these disadvantages are apparently outweighed from an employer's perspective by opposing factors in the recruitment process

When silence means acceptance: Understanding the right to silence as a linguistic phenomenon

This article presents a linguistic analysis of police-suspect interviews with a focus on the right to silence. The author, a linguist, seeks to introduce the legal community to a linguistic understanding of the way that a person might invoke their right to silence and explain how the rules of conversation will have a critical impact on the potential for adverse inference. Extracts from police interviews are analysed using a Conversation Analysis framework, drawing on the notion of 'preference' and adjacency pair structures in particular. The analysis finds that a preference for denials following accusations will problematise any attempts by the suspect to offer a non-response to a police accusation and that, in accordance with conversational rules governing preference, non-response will be interpreted by participants and future audiences as an acceptance of the accusation

Helping the police with their enquiries: Enhancing the investigative interview with linguistic research

Since the UK Police and Criminal Evidence Act introduced tape recorders to police interview rooms in 1984, the insights gained from audio- (and, more recently, video-) recorded police interview data have enabled forensic psychologists to analyse the cognitive and behavioural processes of interview participants, leading to sweeping changes in the way that interviewing is taught and practised by British police officers. However, less attention has been paid to the language of police interviewing and police interviewing methods practised in other parts of the world, such as the Reid Technique, which is ubiquitous in North America. This paper seeks to address both these deficiencies by introducing a linguistic perspective to the analysis of data drawn from an Australian corpus of recorded police interviews. This analysis examined the 'roles' that speakers take up when producing talk as a way of showing how the speaker aligns to the content of the talk. It finds that voluntary confessions by suspects differ in role alignments from police assertions. When evaluating the quality of evidential information obtained in an interview, it is critical to the robustness of the case that the brief is prepared on the basis of volunteered information and not police suggestions. Linguistic theory about role alignments provides a simple tool for distinguishing between talk that is initiated by the suspect and represents new intelligence in the interview, and information that is introduced by the polic

A Local Hubble Bubble from SNe Ia?

We analyze the monopole in the peculiar velocities of 44 Type Ia supernovae (SNe Ia) to test for a local void. The sample extends from 20 to 300 Mpc/h, with distances, deduced from light-curve shapes, accurate to ~6%. Assuming Omega_m=1 and Omega_lambda=0, the most significant deviation we find from the Hubble law is an outwards flow of (6.6+/-2.2)% inside a sphere of radius 70 Mpc/h as would be produced by a void of ~20% underdensity surrounded by a dense shell. This shell roughly coincides with the local Great Walls. Monte Carlo analyses, using Gaussian errors or bootstrap resampling, show the probability for chance occurrence of this result out of a pure Hubble flow to be ~2%. The monopole could be contaminated by higher moments of the velocity field, especially a quadrupole, which are not properly probed by the current limited sky coverage. The void would be less significant if Omega_m is low and Omega_lambda is high. It would be more significant if one outlier is removed from the sample, or if the size of the void is constrained a-priori. This putative void is not in significant conflict with any of the standard cosmological scenarios. It suggests that the Hubble constant as determined within 70 Mpc/h could be overestimated by ~6% and the local value of Omega may be underestimated by ~20%. While the present evidence for a local void is marginal in this data set, the analysis shows that the accumulation of SNe Ia distances will soon provide useful constraints on elusive and important aspects of regional cosmic dynamics.Comment: 21 pages, 3 figures. Slightly revised version. To appear in ApJ, 503, Aug. 20, 199

Quasar-galaxy and AGN-galaxy cross-correlations

We compute quasar-galaxy and AGN-galaxy cross-correlation functions for samples taken from the \cite{VCV98} catalog of quasars and active galaxies, using tracer galaxies taken from the Edinburgh/Durham Southern Catalog. The sample of active galaxy targets shows positive correlation at projected separations $r_p < 6 h^{-1} Mpc$ consistent with the usual power-law. On the other hand, we do not find a statistically significant positive quasar-galaxy correlation signal except in the range $3 h^{-1} Mpc < r_p < 6 h^{-1} Mpc$ where we find similar AGN-galaxy and quasar-galaxy correlation amplitudes. At separations $r_p<3 h^{-1} Mpc$ a strong decline of quasar-galaxy correlations is observed, suggesting a significant local influence of quasars in galaxy formation. In an attempt to reproduce the observed cross-correlation between quasars and galaxies, we have performed CDM cosmological hydrodynamical simulations and tested the viability of a scenario based on the model developed by \cite{silkrees98}. In this scheme a fraction of the energy released by quasars is considered to be transferred into the baryonic component of the intergalactic medium in the form of winds. The results of the simulations suggest that the shape of the observed quasar-galaxy cross-correlation function could be understood in a scenario where a substantial amount of energy is transferred to the medium at the redshift of maximum quasar activity.Comment: 11 pages, 9 figures. Accepted for publication in Ap

The Northern Sky Optical Cluster Survey II: An Objective Cluster Catalog for 5800 Square Degrees

We present a new, objectively defined catalog of candidate galaxy clusters based on the galaxy catalogs from the Digitized Second Palomar Observatory Sky Survey (DPOSS). This cluster catalog, derived from the best calibrated plates in the high latitude (|b|>30) Northern Galactic Cap region, covers 5,800 square degrees, and contains 8,155 candidate clusters. A simple adaptive kernel density mapping technique, combined with the SExtractor object detection algorithm, is used to detect galaxy overdensities, which we identify as clusters. Simulations of the background galaxy distribution and clusters of varying richnesses and redshifts allow us to optimize detection parameters, and measure the completeness and contamination rates for our catalog. Cluster richnesses and photometric redshifts are measured, using integrated colors and magnitudes for each cluster. An extensive spectroscopic survey is used to confirm the photometric results. This catalog, with well-characterized sample properties, provides a sound basis for future studies of cluster physics and large scale structure.Comment: 49 pages, 16 figures. Accepted to AJ; appearing in April. Version with full resolution figures, and full length tables available at http://dposs.caltech.edu:8080/NoSOCS.htm

A Quantitative Evaluation of the Galaxy Component of COSMOS and APM Catalogs

We have carried out an independent quantitative evaluation of the galaxy component of the "COSMOS/UKST Southern Sky Object Catalogue" (SSC) and the "APM/UKST J Catalogue" (APM). Using CCD observations our results corroborate the accuracy of the photometry of both catalogs, which have an overall dispersion of about 0.2 mag in the range 17 <= b_J <= 21.5. The SSC presents externally calibrated galaxy magnitudes that follow a linear relation, while the APM instrumental magnitudes of galaxies, only internally calibrated by the use of stellar profiles, require second-order corrections. The completeness of both catalogs in a general field falls rapidly fainter than b_J = 20.0, being slightly better for APM. The 90% completeness level of the SSC is reached between b_J = 19.5 and 20.0, while for APM this happens between b_J = 20.5 and 21.0. Both SSC and APM are found to be less complete in a galaxy cluster field. Galaxies misclassified as stars in the SSC receive an incorrect magnitude because the stellar ones take saturation into account besides using a different calibration curve. In both cases, the misclassified galaxies show a large diversity of colors that range from typical colors of early-types to those of blue star-forming galaxies. A possible explanation for this effect is that it results from the combination of low sampling resolutions with properties of the image classifier for objects with characteristic sizes close to the instrumental resolution. We find that the overall contamination by stars misclassified as galaxies is < 5% to b_J = 20.5, as originally estimated for both catalogs. Although our results come from small areas of the sky, they are extracted from two different plates and are based on the comparison with two independent datasets.Comment: 14 pages of text and tables, 8 figures; to be published in the Astronomical Journal; for a single postscript version file see ftp://danw.on.br/outgoing/caretta/caretta.p

Observational Mass-to-Light Ratio of Galaxy Systems: from Poor Groups to Rich Clusters

We study the mass-to-light ratio of galaxy systems from poor groups to rich clusters, and present for the first time a large database for useful comparisons with theoretical predictions. We extend a previous work, where B_j band luminosities and optical virial masses were analyzed for a sample of 89 clusters. Here we also consider a sample of 52 more clusters, 36 poor clusters, 7 rich groups, and two catalogs, of about 500 groups each, recently identified in the Nearby Optical Galaxy sample by using two different algorithms. We obtain the blue luminosity and virial mass for all systems considered. We devote a large effort to establishing the homogeneity of the resulting values, as well as to considering comparable physical regions, i.e. those included within the virial radius. By analyzing a fiducial, combined sample of 294 systems we find that the mass increases faster than the luminosity: the linear fit gives M\propto L_B^{1.34 \pm 0.03}, with a tendency for a steeper increase in the low--mass range. In agreement with the previous work, our present results are superior owing to the much higher statistical significance and the wider dynamical range covered (about 10^{12}-10^{15} M_solar). We present a comparison between our results and the theoretical predictions on the relation between M/L_B and halo mass, obtained by combining cosmological numerical simulations and semianalytic modeling of galaxy formation.Comment: 25 pages, 12 eps figures, accepted for publication in Ap

The Aquarius Superclusters - I. Identification of Clusters and Superclusters

We study the distribution of galaxies and galaxy clusters in a 10^deg x 6^deg field in the Aquarius region. In addition to 63 clusters in the literature, we have found 39 new candidate clusters using a matched-filter technique and a counts-in-cells analysis. From redshift measurements of galaxies in the direction of these cluster candidates, we present new mean redshifts for 31 previously unobserved clusters, while improved mean redshifts are presented for 35 other systems. About 45% of the projected density enhancements are due to the superposition of clusters and/or groups of galaxies along the line of sight, but we could confirm for 72% of the cases that the candidates are real physical associations similar to the ones classified as rich galaxy clusters. On the other hand, the contamination due to galaxies not belonging to any concentration or located only in small groups along the line of sight is ~ 10%. Using a percolation radius of 10 h^{-1} Mpc (spatial density contrast of about 10), we detect two superclusters of galaxies in Aquarius, at z = 0.086 and at z = 0.112, respectively with 5 and 14 clusters. The latter supercluster may represent a space overdensity of about 160 times the average cluster density as measured from the Abell et al. (1989) cluster catalog, and is possibly connected to a 40 h^{-1} Mpc filament from z ~ 0.11 to 0.14.Comment: LateX text (21 pages) and 12 (ps/eps/gif) figures; figures 5a, 5b and 6 are not included in the main LateX text; to be published in the Astronomical Journal, March issu

The Nearby Optical Galaxy Sample: The Local Galaxy Luminosity Function

In this paper we derive the galaxy luminosity function from the Nearby Optical Galaxy (NOG) sample, which is a nearly complete, magnitude-limited (B<14 mag), all-sky sample of nearby optical galaxies (~6400 galaxies with cz<5500 km/s). For this local sample, we use galaxy distance estimates based on different peculiar velocity models. Therefore, the derivation of the luminosity function is carried out using the locations of field and grouped galaxies in real distance space. The local field galaxy luminosity function in the B system is well described by a Schechter function. The exact values of the Schechter parameters slightly depend on the adopted peculiar velocity field models. The shape of the luminosity function of spiral galaxies does not differ significantly from that of E-S0 galaxies. On the other hand, the late-type spirals and irregulars have a very steeply rising luminosity function towards the faint end, whereas the ellipticals appreciably decrease in number towards low luminosities. The presence of galaxy systems in the NOG sample does not affect significantly the field galaxy luminosity function, since environmental effects on the total luminosity function appear to be marginal.Comment: 35 pages including 7 figures and 4 tables. Accepted for publication in Ap