"investigation" - key terms from Wikipedia

accident investigation
accident investigation	and the issuing
air crash investigation
background investigation
balco investigation
bombing investigation
bureau of investigation
cbi investigation
central bureau of investigation
cia leak grand jury investigation
columbia accident investigation	board
columbia crew survival investigation	report
committee for the scientific investigation
crash scene investigation
crime scene investigation
criminal investigation
criminal investigation	bureau
criminal investigation	department
criminal investigation	division
detective investigation	files iv
duties such as accident investigation
federal bureau of investigation
formal investigation
grand jury investigation
internal investigation
investigation
investigation	aired
investigation	and restoration
investigation	branch
investigation	bureau
investigation	division
investigation	into the outbreak
investigation	team
kira investigation
kira investigation	team
murder investigation	team
national bureau of investigation
night investigation
ntsb investigation
official investigation
open an investigation
paranormal investigation
police investigation
preliminary investigation
safety investigation
scientific investigation
special investigation	branch
ufo investigation
united states army investigation
watergate investigation