Final answer:
The exciting development in criminology mentioned by Ally Fattah is the widespread decline in crime rates over the past twenty-five years, influenced by demographic changes and new crime prevention strategies.
Step-by-step explanation:
Ally Fattah refers to the global decline in crime rates as "one of the most exciting developments in criminology in the past twenty-five years."
This observation comes amidst various studies and analyses that indicate a downward trend in crime, not just in the United States, but internationally as well. Factors contributing to this decline include demographic shifts, such as the aging of the post-war baby boomers, which has led to a decrease in the population within the prime criminal age cohort.
Additionally, the examination of alternative strategies to mass incarceration, like drug substitution programs, and the impact of education on crime rates have been central themes in recent criminological research.