An American Samoan policeman, Lieutenant Malo Te'o, who is facing charges of tampering with evidence, has made a motion to dismiss the government's case against him.
His lawyer, Robert Maez, is arguing there is a lack of evidence and defects in the supporting affidavit.
The government has alleged that Lt Te'o tried to stop the investigation of two subordinates who had been accused of raping a juvenile detainee.
Mr Maez claims the charge is defective.
He says the government left out a significant portion of the charge relating to intent.