National Research Institute of Police Science

Preliminary Classification of Black Writing Pen Inks Using Optical-probing Photoacoustic Measurement by Pulsed Laser Excitation Combined with Machine Learning for Forensic Applications

Abstract We successfully measured the photoacoustic (PA) signals of black inks in solution from marking pens using a combination of optical-probing photoacoustic spectroscopy (OPPAS) with nanosecond pulsed laser excitation. OPPAS is a highly sensitive technique that detects heat...

The Effects of Homicides on Childcare Classroom Quality and Child Development

Community violence exposure (CVE) can disrupt children’s learning. This study examines how recent homicides near early childhood education providers (ECEPs) affect classroom quality and child outcomes in Colombia. We use data collected from low-income children (age: M = 45.35 mon...