agencies are investigating, but mark lenzi has a theory. >> lenzi: this was a directed standoff attack my apartment. >> pelley: it was a weapon? >> lenzi: oh, of course it was a weapon. >> pelley: an energy weapon? >> lenzi: absolutely. >> pelley: what sort of energy is this that we're talking about? >> lenzi: i believe it's r.f., radio frequency energy, in the microwave range. >> pelley: a clue that supports that theory was revealed by the this n.s.a. statement describes such a weapon as a "high-powered microwave system weapon that may have the ability to weaken, intimidate, or kill an enemy over time without leaving evidence." the statement goes on to say, "this weapon is designed to bathe a target's living quarters in microwaves." the n.s.a. disclosed this in a worker's compensation case, filed by former n.s.a. employee mike beck. >> pelley: when you look back across your career, is there any incident that leads you to believe that it could be responsible for your parkinson's disease? >> mike beck: yes. >> pelley: in the 1990s, beck and an n.s.a. coworker were on assignment overseas

. >> mark lenzi is a state department security officer who worked in the u.s.sulate in guangzhou, china. >> there is no shadow of a doubt in my mind that this was a directed attack against my neighbor and i. >> his neighbor was catherine werner. >> it was intense pressure on both of my temples. and i remember looking around for where this sound was coming from, because it was painful. >> thank you. >> have a great tour. >> steve case is a billionaire