American Samoa's Chief Justice Michael Kruse has accepted the plea agreement from former policeman Papalii Marion Fitisemanu.
Papalii was initially charged with four counts of embezzlement and possession of a prohibited weapon, and in August he entered a plea of no contest to unlawful possession of a prohibited weapon.
The other charges have been dropped.
The Chief Justice said even though Papali'i pleaded no contest, the pre-sentence report by the probation office shows that he either forgot to turn in the weapon or didn't bother to turn it in at all to police.
Police investigating the case retrieved the weapon, an assault rifle from Papalii's home.
The Chief Justice said the court will accept the plea agreement but is not ready for sentencing at this time.
Papalii a 20-year police veteran was accused of taking five weapons from the custody of police and sending four to Samoa's Police Commissioner while he kept a fifth weapon.