Police have arrested a man accused of placing two cardboard cutout images of crashing planes at the 9/11 monument in downtown Lafayette.
According to CNN, each plane had the letters "NWO" and an image of an eye in a triangle, a reference to the New World Order conspiracy theory.
The theory includes the belief that the 9/11 attacks were carried out by the U.S. government.
Salvador Perez, 35, of Lafayette, was booked into the Lafayette Parish Jail on charges of criminal damage to a historic building and criminal trespassing.
Bond information was not available on Wednesday afternoon.
The investigation continues.
Police say they were notified of the graffiti around 8 a.m. Wednesday.
KATC TV reports the 9/11 monument is a 1-by-100 scale of both the World Trade Center and the Pentagon. It includes three beams from the World Trade Center, limestone from the Pentagon, and soil from the Shanksville, Penn., field in which Flight 93 crashed.
The monument was dedicated on Sept. 11, 2002, the first anniversary of the terrorist attacks.
Copyright 2013 KPLC. All rights reserved. The Associated Press contributed to this report.