Alma 47:26 - 47:30
Alma 47: 26 Behold, the servants of the king have stabbed him to the heart, and he has fallen and they have fled; behold, come and see.
These murders of the king then yelled that the servants of the king were the ones that killed him. The fact they were running away was evidence of that.
Alma 47: 27 And it came to pass that Amalickiah commanded that his armies should march forth and see what had happened to the king; and when they had come to the spot, and found the king lying in his gore, Amalickiah pretended to be wroth, and said: Whosoever loved the king, let him go forth, and pursue his servants that they may be slain.
Then the army of Amalickiah were brought up to see the dead killed lying in his blood. Amalickiah pretended to be very angry and commanded that some of his army chase the servants of the king and kill them.
Alma 47: 28 And it came to pass that all they who loved the king, when they heard these words, came forth and pursued after the servants of the king.
Those who had had great regard for the king, then took after these servants trying to caught them so they could be put to death.
Alma 47: 29 Now when the servants of the king saw an army pursuing after them, they were frightened again, and fled into the wilderness, and came over into the land of Zarahemla and joined the people of Ammon.
When the servants could see the army coming for them, they ran into the wilderness towards Zarahemla. There they sought for asylum and then joined up with the people of Ammon.
Alma 47: 30 And the army which pursued after them returned, having pursued after them in vain; and thus Amalickiah, by his fraud, gained the hearts of the people.
The army of Amalickiah were unable to catch the rapidly fleeing servants of the king and returned to Amalickiah. So by the murders of various individuals including the king, Amalickiah now had the loyalty of the army and the Lamanites in general.