National Defender Investigator Association (NDIA) 

http://www.ndia.net/

Professional Investigators of California   (PICA)

http://pica-association.org/

California Bail Agents Association (CBAA)

http://cbaa.com/

Golden State Bail Agents Association  (GSBA)

https://gsbaa.org/

Investigators of America (IOA)

http://www.investigatorsofamerica.com/

National Association for Public Defense (NAPD)

http://www.publicdefenders.us