Louis confirmed that Gerard had told him the same story a year earlier. This is the latest example of a crime investigation culminating with crucial evidence provided by a member of the suspect's close family. Often, the public reacts with surprise when someone like Capano or Unabomber suspect Ted Kaczynski is turned in by a family member. In fact, it is a fairly common occurrence. Nearly every criminal lawyer can tell stories about relatives who have called the police, provided an anonymous tip, or taken the witness stand.
Authorities say such cases fall into predictable patterns.
Geberth notes that the greater the public outrage, the more likely a family member will cooperate with police. David Kaczynski fingered his brother Ted as the possible Unabomber because he feared for future victims and believed Ted was dangerously deranged. Like David Kaczynski, Joe Adam Cantu felt he had no choice but to turn in his kin. In June 1993, Cantu was at home in Houston, when his younger brother Peter, the leader of the Black and White Gang, came by along with three other gang members, laughing that they had just raped and killed two teenage girls. Cantu listened horror-struck, and later phoned in an anonymous tip, telling the police where to find the bodies.