Mr Trump said government agencies must work together and identify individuals who may commit violent acts, prevent their access to firearms and also suggested involuntary confinement as a way to stop potential attackers.
The president criticised the internet and "gruesome" video games for promoting violence in society.
"It is too easy today for troubled youth to surround themselves with a culture that celebrates violence," he said. "We must stop or substantially reduce this and it has to begin immediately."
https://www.bbc.co.uk/news/world-us-canada-49240310
