Book excerpt: Criminal Justice Handbook on Masculinity, Male Aggression, and Sexuality discusses masculinity as a social construct, an ideal, and an impediment for males and females. The book explores how the law equalizes, protects, bridles, and enforces masculinity while dealing with crime, which often exploits and exaggerates masculinity. Among the topics addressed are historical and contemporary law, scientific understandings, issues in corrections, military service, the court system, policing, criminal procedure, medicine, and treatment. Because masculinity is often exhibited as a gender role, the book examines aggressive behaviors, emotional responses, interpersonal rules, appearances, sexual desires, and other aspects of human dynamics that may restrict or enhance masculinity. Juveniles are discretely discussed in subsections concerning masturbation, bullying, risk, sexual assault, pornography, and their susceptibility to victimization by peers and adults. Physical differences between males and females are relevant to criminal justice processes and includes bone shape and size, voices, appearance, scent, and genitalia. The male genitalia is thoroughly discussed in the sections dealing with unlawful penetration, male working animals, forensics, sex offenders, frisks and searches, penile injuries, prostheses, obscenity and lewd behavior, transgenderism, and human trafficking. Unique features include: male and female perpetrators of domestic violence, illegal immigration, drug and alcohol trafficking, gangs and gang members, homosexual victims of hate crimes, and the use of steroids. In addition, illustrations are included to clarify specific points. This text will be an excellent resource for careers in correctional education, juvenile justice, criminal justice and male aggression, law enforcement, sociology, and psychiatry.