Quote Originally Posted by psychocat
I have been able to find some statistics regarding legal guns used in school shootings , if you have links to prove your claim I would be interested in reading them.

My research suggests the majority of the firearms used in these events were obtained from perpetrators' homes or the homes of friends or relatives.

Source of Firearms Used by Students in School-Associated Violent Deaths --- United States, 1992--1999

In a study of 65 high-profile multiple-victim shootings in the United States over a period of 40 years, 62% of handgun shootings and 71% of long gun shootings were committed with legally acquired firearms.

Gun Facts - Mass Shootings

Feel free to dispute this but only with hard facts.
Well, here is a quote from your 1st link. The findings in this report are subject to at least four limitations. First, because events were identified from news media reports, any event not reported in the media was excluded. Second, this report includes events associated with schools; other homicide and suicide events involving school-aged perpetrators might have different firearm-acquisition patterns. Third, the results reported for homicide events might not reflect the true distribution of sources because the source of the firearms in approximately 25% of these events is unknown. Finally, among the student perpetrators who obtained their firearms from home or from friends or relatives, how the students gained access to these firearms is unknown.

They do not know where 25% of the guns came from, and the rest they don't know how they were obtained, so according to these FACTS how can you say "I would be willing to bet that most of the weapons used in school shootings are owned by the culprit and also fully legal."
Stealing from family is still stealing, and according to most of the reports that I read at the time of those shootings, the perpetrators did not have permission from the owners of those guns.
Now, I am only talking about the US. Minors cannot legally purchase firearms.

I'm done with this. We will have to agree to disagree.