Siebe: You have probably not read the whole account of Angulimala before commenting: “Angulimāla – A Murderer’s Road to Sainthood“.
– I had provided this link in the post: “Account of Angulimāla – Many Insights to Buddha Dhamma”
Local authorities were too scared to confront Angulimala, and the King himself came with an army to catch him. But the Buddha intervened before that.
The King thus met Angulimala, who was sitting by the Buddha, when he arrived with the army. Angulimala was already an Arahant by that time. There was no need for the King to arrest Ven. Angulimala.