The Boulder, Colorado mass shooting last week was followed by one in Virginia.
Ahmad Al Aliwi Alissa, whose family emigrated to the U.S. from Syria, is charged in the Boulder tragedy.
Some of those who know him say he may suffer from mental illness, "had a temper," was anti-social, and had grown increasingly paranoid.
He is charged with 10 counts of first-degree murder and one charge of attempted murder after the rampage Wednesday.
The New York Times reported that Ahmad Alissa was already on the FBI’s radar because he was linked to another individual who is under investigation by the FBI. That's been the case in numerous mass shootings in the U.S.
On Friday, there were two mass shootings in Virginia Beach, blocks apart, that did not get as much attention.
At least 10 people were shot; two of them died.
Charged in those cases are: Ahmon Adam, Nyquez Baker, and Devin Dorsey, Jr.