The Class Characteristic Mark of the H&M Mul‐T‐Lock Picking Tool in Toolmarks Examination

Abstract

Mul-T-Lock is a high security lock cylinder distinguished by the use of a telescoping "pin-in-pin"-tumbler design. Picking the Mul-T-Lock cylinder with a traditional picking tool is highly complicated because it can get stuck between the inner and outer pins. The H&M Mul-T-Lock picking tool was designed to overcome this problem and facilitate the picking of the "pin-in-pin" cylinder. The purpose of this research is to determine whether H&M Mul-T-Lock picking tool leaves class characteristic mark and whether it can be distinguished from traditional picking tools marks and from regular key marks. It also describes and determines the class characteristic mark left on telescopic pins, its origin, recurrence, and its benefit to the toolmarks examiner. When receiving a Mul-T-Lock from a crime scene, a toolmarks examiner can quickly determine whether or not it was picked by an H&M Mul-T-Lock picking tool by noticing the class characteristic mark which this typical tool leaves.

Computational analysis of thermal-motion effects on the topological properties of the electron density

“…In pursuit of this goal, we generate a large ensemble of geometries (M = 500 000 nuclear configurations) consistent with the harmonic internal vibrations of the formamide molecule. To each nuclear configuration of this ensemble, an approximate 'single-point' wavefunction is calculated and the topology of the corresponding static ED is derived (Volkov et al, 2009) to obtain an ensemble of static BTPs, which forms the basis of the subsequent statistical analysis.…”