This research textbook provides a comprehensive analysis that explores the importance of English instruction in the professional development and job readiness of non-native English-speaking (NNES) peace officers in the United States. The research highlights these officers' challenges and successes and emphasizes the crucial role of specialized legal English training in enhancing their communication skills, job performance, and community engagement. The objectives include examining linguistic and cultural barriers, discussing the specific linguistic and cultural challenges that NNES peace officers encounter, and analyzing how these issues impact their work performance and involvement with the community. The insights and findings presented in this work would be valuable to a broader audience, including researchers, institutions that offer legal English education, legal practitioners, and students.