Defense Technology and Federal Laboratories merged in 2001. They are owned by umbrella company Safariland. Safariland was owned by UK weapons conglomerate BAE systems, a large conglomerate which owns some 400 other companies, before it was bought by war profiteer Warren B. Kanders, (though the sale was held up by the sentencing of a former Safariland executive for bribing government officials in Europe, Africa, and the Middle East in order to secure business). Kanders was CEO of body armor manufacturer Armor Holdings (which owned Safariland) when Armor Holdings was sold to BAE Systems. Some of this complicated story is explained on Safariland's website.
Pennsylvania-based Federal Laboratories has existed for at least the better part of a century, and manufactured the first police batons with tear gas in 1925. Safariland holds monthly trainings for cops, prison officers, private security personnel, and active-duty soldiers across the U.S. in how to use this Chemical Weapon. Both Federal Laboratories and Defense Technology sell to the Israeli military, although since Federal Laboratories' acquisition, the Defense Technology brand has become more common.
Evidence of their use in different countries
Mexico - 1
Turkey - 1
“Tracking Tear Gas” by Occupy Wall Street Global Justice Working Group
"The Safariland Group Story" from the Safariland website.
"More Deaths and Injuries from US Tear Gas in Palestine, around the Middle East, and in Oakland"