Dr Ndikaru wa Teresia takes a look at criminology as a social science, which deal with law making, law breaking and responses to crime. Criminology ascertains principles for distinguishing criminal and non-criminal behavior. It categorizes various types of crimes and criminals, approves right and proper punishment for criminals. The author evaluates the fundamentals of criminology which are social science theory, research methods and the criminal justice system which includes the police, courts and corrections. The justice system has developed into a major social institution in Kenya and world at large. The author presents penology as concerned with punishment, the justification of punishment, preventing and controlling crime. This book will be helpful to lecturers and students in university and scholars who are doing more research on Criminology and Penology.