The police have arrested a man who they say delivered the "final blow" that killed Captain Mahama when he was killed by a mob last Monday.
Police say the man, Kwame Tufour, used a cement block to hit the army officer, resulting in his death.
The man is said to have run away after the act, but residents of the town tipped the police off to his location.
The police caught him with one Kwame Adjei, 40, who is believed to have participated in the killing of the captain.
During interrogation, he told the police that when he arrived at the scene, Captain Mahama had already been killed and that he used a block to hit the captain's dead body.
The captain had been spotted carrying a pistol by some women he had bought snails from and the women who, police say, assumed he was a robber, called the assembly man and reported that they had seen.
Police say the assembly man, without finding out if the information was correct, quickly rallied members of the town to attack and kill the captain.
The news will come as a blow to Ghanaians who have been campaigning for an end to mob violence.
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