CANADA官方网站有这一说：You and your family members must provide us with a police certificate issued by the authorities of each country in which you have lived for six (6) months or more since reaching the age of 18.
Certificates must be originals and issued within the last three months.
不知什么机构可以作the authorities of one country for a police certificate? 中国的证明能否用在公证处办的无罪公证，几年前出国时办的。当然这样三个月的要求是满足不了啦。请有经验者指正。多谢！