Officials at Arlington Cemetery found the cremated remains of eight people buried in one grave in October.
Army officials have launched a criminal investigation: They want to know how multiple sets of cremated remains at Arlington Cemetary ended up in a single grave.
A cemetary spokeswoman says officials found the remains of eight people buried in one spot back in October, with a headstone marked "unknown."
Since then, investigators have identified three sets of the remains: one set couldn't be identified and was reburied with an "unknown" marker. Investigators are still working to ID the other remains.
A spokesman for the Army Criminal Investigation Command said that the placement of eight urns in one grave was unlikely to be a mistake.
A report out earlier this year found that more than 200 graves had been mis-marked on cemetary maps.