GAO says ` ` early detection '' missed 16 alleged incidents . Initial efforts to spot suspicious behavior began in 2003 . 3,000 specially trained TSA offices work in 161 U.S. airports . Zazi pleaded guilty to providing material support to al Qaeda . NASA says TSA is ` ` an agency in total ' ''
GAO says ` ` early detection '' missed 16 alleged incidents . Initial efforts to spot suspicious behavior began in 2003 . 3,000 specially trained TSA offices work in 161 U.S. airports . NASA says TSA is ` ` an agency in total ' ''