Delator (plural Delatores) is Latin for a denouncer, i.e. who indicates to a court another as having committed a punishable deed.

to press charges against
to file criminal charges against somenone
to bring criminal charges against

to denounce = to report someone to the authorities



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Note added at 36 mins (2007-02-06 20:46:04 GMT)
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- to report a crime http://www.miamishoresvillage.com/Police/report_a_crime.htm