Virginia Tech University gunman Cho Seung-Hui penned a “disturbing note” before going on a shooting spree which left 32 people dead, police have revealed.

The twenty-threeyear-old South Korean student killed his first victim, 18-year-old Emily Hilscher, before he went on the rampage and blasted to death whoever was in range.

Police sources said a “disturbing note” left in his room contained a bomb threat and that he probably went back there to re-arm during his deadly spree.

The note is reported to have contained the line “You made me do this”.

Reports say the English undergraduate’s creative writing was so “troubled” that Seung-Hui had been referred by teachers to the school’s counselling service.

Here are some of the theories currently under investigation include:

• The killer and Hilscher were an item and it was an argument between them over another student which sparked the slaughter

• Seung-Hui was obsessed with Hilscher and wanted to be with her but she had refused his advances leading him to go on the rampage

• The bitter gunman despised rich students and went on the rampage to kill those with money