From the beginning of the manhunt for the marathon bombers, one question stood out: why did the Tsarnaevs kill MIT Police Officer Sean Collier and trigger a massive manhunt? Why weren’t they a three-day drive away from Boston? How could they have been so stupid to force a confrontation with a cop? Officials didn’t yet know who the bombers were. Officer Collier wouldn’t have known they were the bombers. Of course, we know now that they killed him execution style, so it doesn’t appear that they overreacted to some sort of inadvertent encounter. So, the question remains: why invite the attention?

Maybe they killed Officer Collier to trigger the manhunt.

It would explain a lot. Why they stayed in Watertown after the bombings. Why they were equipped with a car full of more explosives. Maybe even why they carjacked the SUV. They knew they were going to get identified. And, when they did, they wanted to go out in a hail of gunfire and shrapnel, taking down as many cops as they could. When they weren’t identified quickly enough, they poked the law enforcement dragon. In the end, the younger Tsarnaev — alone and injured and exhausted — just didn’t see the plan all the way through.

If that’s what they intended, it is remarkable — and very lucky — that more people weren’t killed or injured in the hours following the execution of Officer Collier.

Makes this all look a lot more like Columbine than terrorism. Two disaffected young men wanting everyone to know their names.