He co-chaired the National Commission of Forensic Sciences (NCFS) invoked by the Attorney General in 2013, to enhance the practice and improve the reliability of forensic science. The NCFS was terminated on April 23, 2017 following the presidential administration change and has published a business document both reflecting on the work done and the future work ahead.

Butler has written several widely recognized textbooks on forensic DNA profiling covering all aspects of the underlying molecular genetic methods, the application to forensic casework and the biostatistical interpretation of results. He received the Scientific Prize of the International Society for Forensic Genetics in 2003.