[yvonne]

When I was in elementary school, an emotionally disturbed man blew himself, his son, a teacher, a custodian, and two other students up at an elementary school just 4 miles away.  Many more would have died had the teacher not recognized the situation and sent away a number of students whom the man had told to gather around him.  There were no prior threats. 

After the blast, there was no trace of the perpetrator.  The police had to presume he got away and might attack other schools.

I'm confused.

[yvonne]

When I was in elementary school, an emotionally disturbed man blew himself, his son, a teacher, a custodian, and two other students up at an elementary school just 4 miles away.  Many more would have died had the teacher not recognized the situation and sent away a number of students whom the man had told to gather around him.  There were no prior threats. 

After the blast, there was no trace of the perpetrator.  The police had to presume he got away and might attack other schools.

I'm confused.