Feds: Most school shooters tip off their plans

Law enforcement sources told CBS News that TJ Lane, the suspect in the Chardon, Ohio high school shooting that left two students dead and three wounded, told other people of his intentions two days in advance.

That's apparently not uncommon.

After the Columbine High School shootings in 1999, the Secret Service did an exhaustive study, and what they found was that school shooters are all boys - 85 percent white, 12 percent black, the rest mixed - and the shooters cross all socio and economic stratospheres.

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In those cases, you've got people who had difficulty coping with loss, who felt bullied or picked on. Most had access (to) or had used weapons before.

But the shocking stats were that, in 81 percent of these cases, they told people this is what they were going to do. In only 4 percent of these cases, across more than 100 school shootings, did people try to dissuade them from it, and in several cases, people said threatening them with a gun isn't enough. You have to up the ante and actually shoot people.

The key lesson: If people are talking that way, whether it's taking their own life or others', even if you think they're just talking, you've got to report that to school administrators, parents and police.