Answer: 3 years
Explanation: IACIS( International Association of Computer Investigative Specialists) is organization made in 1990 which takes care of the processing in the computer forensics.It is a non profit organization which gives the training and services related to the membership .
It operates voluntarily and keeps the pace with the changing computer technology with the help of the advanced computer tools. In every 3 years of time period re-certification of IACIS is done for their working.