In ancient times, just like the police, when a prisoner wanted to be arrested, they had to show their certificates. They are a kind of waist tags, which can be used to prove their identity when performing official duties. If a case needs a warrant or a search, they also need to consult their superiors and get paper documents before they can act.
There was also a system of arresting officials in ancient times. A county government may have more than forty arresters, but when dealing with specific cases, one arrestor will take one or two deputies, and the deputies will call several assistants. This makes many hands make light work. Some criminals are fierce, and no one can be suppressed. These helpers are temporary workers.
In fact, the identity and status of ancient arresting officers are relatively humble. If the arresting officers in the Qing Dynasty want to hold their heads high, they have to wait for three generations to take the imperial examination. So in ancient times, the threshold for being a policeman was very low. As long as you are quick and smart, you can be a policeman, including illiterate farmers and criminals with criminal records. This profession is not a civil servant, but a person who works for the public.
Moreover, in ancient times, the wages of arresting officers were not high, and they earned very little, and these people were not from serious backgrounds. Usually when they are on official business, it is also the time when they earn income. Eating and getting cards has become a routine, and sometimes even for greater benefits, officials and businessmen collude privately to deliberately create unjust, false and wrong cases in order to obtain benefits.
During the period of Song Shenzong, in order to correct the corruption of officials, it was decided to pay them a monthly salary, which was small, but it was also a stable income, and the local police also had some fixed salaries. Income generation? Money, but also a considerable income, so the people who worked for the public in the Song Dynasty were suddenly overcrowded.