Diplomatic immunity is a form of legal immunity and a policy held between governments, which ensures that diplomats are given safe passage and are considered not susceptible to suit under the host country's laws (although they can be expelled as undesirable - persona non grata). It was agreed as international law in Vienna Convention on Diplomatic Relations (1961). It is possible for the official's home country to waive immunity; this tends to only happen when the individual has committed a serious crime, unconnected with their diplomatic role (as opposed, to, say, allegations of spying), or has witnessed such a crime. Alternatively the home country may prosecute the individual.

Diplomatic and Consular Privileges and Immunities From Criminal Jurisdiction

Summary of Law Enforcement Aspects

Category		May Be Arrested or Detained	Residence May Be Entered Subject to Ordinary Procedures	May Be Issued Traffic Citation	May Be Subpoenaed as Witness	May Be Prosecuted	Recognized Family Member
Diplomatic	Diplomatic Agent	No1	No	Yes	No	No	Same as sponsor (full immunity and inviolability)
	Member of Administrative and Technical Staff	No1	No	Yes	No	No	Same as sponsor (full immunity and inviolability)
	Service Staff	Yes2	Yes	Yes	Yes	No, for official acts. Otherwise, yes2	No immunity or inviolability2
Consular	Career Consular Officers	Yes, if for a felony and pursuant to a warrant.2	Yes4	Yes	No, for official acts. Testimony may not be compelled in any case.	No, for official acts. Otherwise, yes3	No immunity or inviolability2
	Honorary Consular Officers	Yes	Yes	Yes	No, for official acts. Yes, in all other cases	No, for official acts. Otherwise, yes	No immunity or inviolability
	Consular Employees	Yes2	Yes	Yes	No, for official acts. Yes, in all other cases	No, for official acts. Otherwise, yes2	No immunity or inviolability2
International Organizations	International Organization Staff3	Yes3	Yes3	Yes	No, for official acts. Yes, in all other cases	No, for official acts. Otherwise, yes3	No immunity or inviolability2
	Diplomatic-Level Staff of Missions to International Organizations	No1	No	Yes	No	No	Same as sponsor (full immunity and inviolability)
	Support Staff of Missions to International Organizations	Yes	Yes	Yes	No, for official acts. Yes, in all other cases	No, for official acts. Otherwise, yes	No immunity or inviolability

¹Reasonable constraints, however, may be applied in emergency circumstances involving self-defense, public safety, or the prevention of serious criminal acts.

²This table presents general rules. Particularly in the cases indicated, the employees of certain foreign countries may enjoy higher levels of privileges and immunities on the basis of special bilateral agreements.

³A small number of senior officers are entitled to be treated identically to “diplomatic agents.”

⁴Note that consular residences are sometimes located within the official consular premises. In such cases, only the official office space is protected from police entry.

This chart is copied from the US State Department's Bureau of Diplomatic Security Web site, http://ds.state.gov/dipimmunities/dichart.pdf.