The people's police can go to the unit or residence of the infringed person or other witnesses to question them; When necessary, they can also be notified to testify in public security organs.
legal ground
Article 82 of the Law on Public Security Administration Punishment requires that those who violate public security administration be summoned for investigation, and with the approval of the person in charge of the case-handling department of the public security organ, a summons card shall be used for summoning. The people's police may summon an offender found on the spot who violates the administration of public security orally after producing his work certificate, but it shall be indicated in the inquiry record.
The public security organ shall inform the summoned person of the reasons and basis for summoning. A person who refuses to accept a summons or evades it without justifiable reasons may be summoned by force.