References in periodicals archive ?
He said he was satisfied O'Keefe, who was a former instructor for weapons technique and survival, didn't know the ammunition contained substances and nor did experts until further analysis revealed a trace of CN gas, used as a tear gas.
Many protesters in Cairo have suspected the use of CN gas but Daily News Egypt has seen no evidence to support this.
An added surprise was a pronounced increase in the amount of CN gas in the comet's coma.