Ronald M. McCarthy served as a Los Angeles police officer for over twenty-four. He was assigned to the department's tactical unit, Metro Division, for 20 years and retired from Special Weapons and Tactics as the senior supervisor and assistant commander in 1984. Ronald McCarthy was the chief of Tactical Operations for the U.S. Department of Energy from 1984 through 1986. He was the director of the Deadly Force Training Grants for the U.S. Department of Justice and the International Association of Chiefs of Police (IACP) from 1986 through 1988. Ronald McCarthy served as manager for IACP's Center for Advanced Police Studies from 1985 through 1992.

Since 1992, Ronald McCarthy has been the owner of R.M. McCarthy & Associates, a training, consulting, and marketing resource for law enforcement. He has trained police officers from Europe, South America, the Middle East, and more than 30,000 police officers and military here in the United States.

Ronald McCarthy was awarded the Los Angeles Police Department Medal of Valor for action against the Symbionese Liberation Army in 1975, and the Police Star for the rescue of hostages in 1983. He was presented with the National Tactical Officers Association Award for Excellence in 1990. In 1995 the City of Erie, Pa., presented him with the All American Hero Award for his service to law enforcement throughout the United States. In October of 1996, Ronald McCarthy was awarded the National Tactical Officers Association's Lifetime Achievement Award.

Ronald McCarthy is the co-author of The Management of Police Specialized Tactical Units.  According to the book description, “Managerial responsibility of a SWAT team requires continuous research in the material area of long-term criminal trends as well as keeping abreast of new developments in relevant tactics, technology, and techniques of law enforcement and the legal issues covering their use. The Management of Police Specialized Tactical Units explains the steps for developing and maintaining a realistic, effective response to increasing levels of violent crime. The book makes extensive use of actual field examples such as the North Hollywood Bank of America Shootout, the Mogadishu Airport Incident, the Springle Street Incident, and the confrontation between police and the Symbionese Liberation Army. Chapter Six discusses the various types and sources of equipment designed to give tactical units more effective technological choices and includes examples of practical application, and the advantages and disadvantages of use. It answers questions of law regarding when and under what circumstances the equipment may be used. Chapter Ten focuses on the partnership needed between law enforcement and the media. The importance of cooperation is stressed to ensure safety of police officers, hostages, news personnel, and bystanders during a hostage situation. Suggestions for establishing trust and credibility are presented. The final chapter explores tactical operations of the future when dealing with increasingly violent encounters with juvenile offenders, the phenomenon of “suicide-by-cop,” and the likelihood of terrorist use of weapons of mass destruction."