3.1 Data Preprocessing The raw data from telephone service providers is the telephone numbers and their detail records of outgoing calls or incoming calls of the suspects telephone to be investigated. Several main attributes of the data we examine are Tele_number, Call_kinds, Start_time, Location, and Duration. The classes are suspect, partner and none. To fuzzify the data, we defined several sub attributes: 1) In Call_kinds, call and called present that the owner of the telephone called the suspect or was called by the suspect; 2) early, in-day, and later in Start_time denote the telephone conversation took place before, at or after the day that the crime is conducted; 3) inside and outside in Location present that the owner of the telephone was or was not in the same city (the region of a base station) with the suspect during their telephone conversation; 4) long, mid and short in Duration present the time spending on a telephone conversation.