Online rants by would-be shooters create dilemma for police

BOISE, Idaho (AP) — The perpetrators of mass shootings often provide a treasure trove of insight into their violent tendencies on social media. But the information is not always seen by law enforcement until after the violence is carried out.

Retired federal law enforcement agent David Chipman says there are lots of people saying vitriolic things on social media and it’s tough to know who is just talking and who is going to carry out violence.

The gunman accused of opening fire at a synagogue in Pittsburgh expressed virulently anti-Semitic views on a social media site. But it was only just before the shooting that the poster believed to be Robert Bowers seemed to cross the line from talking to action by posting: “I’m going in.”