TUCSON, Ariz. - Mass shooters give out plenty of warnings and usually use guns they bought legally those are some of the conclusions of a new FBI report.
Mass shooters usually plan their attacks long before they happen -- and give off signs that offer a chance to prevent mass murders.
Some of the findings fit Tucson's mass shooting of January 8, 2011.
To try to prevent more killings, the FBI's behavior specialists analyzed how shooters behaved before they attacked.
They found only 25 percent of the shooters had ever been diagnosed as mentally ill.
Most bought their guns legally and most talked about killing or showed some kind of behavior that should have made people around them suspect they could be a threat.
But 54 percent of people in a position to say something, didn't.
In the case of Jared Loughner, who killed six people and shot thirteen others in Tucson, many people described bizarre, frightening behavior.
But when it came to getting Loughner into treatment, Loughner's father told a detective Loughner closed his ears, He says, "lost, lost and just didn't want to communicate with me no more."
At the National Alliance on Mental Illness, Clarke Romans knows it can be hard to help someone who is not willing but you should not be afraid to try.
"But reaching out to them and asking if they need help and being willing to inform others. It doesn't necessarily have to be law enforcement; it could be family members. It could be friends. It could be church leaders.”
After January 8th local law enforcement developed mental health teams trained to help troubled people get treatment.
Sheriff's Detective Shawn Degan knows people who see threatening behavior may think, he'd never do that.
"Like, 'No I know them,’ but if they're truly in a mental health crisis then they're going to go through these periods of time where they potentially could do that. I'm not saying that's all mental health, whether it's depression, which is something people deal with a lot, it's in those states where people are probably going to be unpredictable where that's where they need the help."