65 ILCS 5/1-4-6
In case any injury to the person or property of another is caused by a member of the police department of a municipality having a population of less than 500,000 while the member is engaged in the performance of his or her duties as a police officer, and without the contributory negligence of the injured person or the owner of the injured property, or the agent or servant of the injured person or owner, the municipality in whose behalf the member of the municipal police department is performing his or her duties as police officer shall indemnify the police officer for any judgment recovered against him or her as the result of such injury, except where the injury results from the wilful misconduct of the police officer, to the extent of not to exceed $1,000,000 including costs of the action. Any police officer, or any person who, at the time of performing such an act complained of, was a police officer, who is made a party defendant to any such action shall, within 10 days of service of process upon him or her, notify the municipality by whom he or she is or was employed, of the fact that the action has been instituted, and that he or she has been made a party defendant to the same. Such notice shall be in writing, and shall be filed in the office of the city attorney or corporation counsel, if there is a city attorney or corporation counsel, and also in the office of the municipal clerk, either by himself, his or her agent, or attorney. The notice shall state in substance, that such police officer, (naming him or her), has been served with process and made a party defendant to an action wherein it is claimed that a person has suffered injury to his or her person or property caused by such police officer; stating the title and number of the case; the court wherein the same is pending; and the date such police officer was served with process in such action, and made a party defendant thereto. The municipality which is or may be liable to indemnify the police officer shall have the right to intervene in the suit against the police officer, and shall be permitted to appear and defend. The duty of the city to indemnify any such policeman for any judgment recovered against him shall be conditioned upon receiving notice of the filing of any such action in the manner and form hereinabove described.
For the purposes of this Section, no civilian defense worker, nor any member of any agency engaged in any civilian defense activity, performing services as a part of any civilian defense program, shall be considered to be a member of a municipal police department.
If any person in obeying the command of any such policeman to assist in arresting or securing an offender is killed or injured, or his or her property or that of his or her employer is damaged, and such death, injury or damage arises out of and in the course of aiding such policeman in arresting, or endeavoring to arrest, a person or retaking or endeavoring to re-take a person who has escaped from legal custody, the person or employer so injured, or whose property is so damaged, or the personal representatives of the person so killed, shall have a cause of action to recover the amount of such damage or injury against the municipal corporation by which such police officer is employed at the time such command is obeyed.
If a police officer is acting within a municipality other than his or her employing municipality under an agreement pursuant to Section 11-1-2.1, the liability or obligation to indemnify imposed by this Section does not extend to both municipalities. Only that municipality designated by the agreement is subject to such liability or obligation to indemnify, but, if the agreement is silent as to such liability or obligation, then the municipality by which the police officer is employed is subject to such liability or obligation.
If a police officer is acting within a municipality other than his or her employing municipality under the provisions of Section 1-4-8, the liability or obligation to indemnify imposed by this Section shall be the liability or obligation of the requesting municipality only. The notice required in this Section 1-4-6 shall be given to the municipality in which he was acting if other than his employing municipality.
65 ILCS 5/1-4-6