The first group of Peoples Temple members to leave that organization were the subject of great concern. This group left PT several years before the deaths in Jonestown. Here is a portion of the book Raven, written by Tim Reiterman, which discusses how Jim Jones and the leadership of PT reacted to those who left:
"Defections of important members threatened the Temple walls from both sides. Inside, defections harmed morale and created danger of a domino effect. But the major concern was that the defectors might goto the press or police. Each prominent defector was a torpedo loaded with explosive secrets. Jones had to either get it back or disarm it somehow.
"Jones followed the same general strategy with most defections. First, he and his aides investigated the circumstances of the defection, looking for a way to level an allegation of theft or misconduct of any sort. Second, Jones decided whether to report the defection to other members or to try and keep it secret and try to get back the defectors. Third, he cast the defectors in villainous roles; he fed the membership's genuine feelings of betrayal and loss by belaboring his own. In that climate, he was able to convince friends and relatives of the defectors to sign affidavits attesting to their dastardly past acts.
"Finally, Jones limited the damage. He partly closed off one avenue to the press and the law by documenting allegations and damaging the credibility of defectors. At the same time, he tried to reestablish contact with the defectors to induce them to come back, or, failing that, never to harm the church. Sometimes he sent heavyweights to intimidate them or blackmail them with their own false written confessions."
Interesting reading, isn't it?