Mexican law is based on the Roman and Napoleonic codes, presuming an accused person guilty until proven innocent.

A law passed in 2009 determined that possession of small amounts of certain drugs for personal use – including cannabis (5g), cocaine (500mg), heroin (50mg) and methamphetamine (40mg) – would not incur legal proceedings against first-time offenders. But those found in possession of small amounts may still have to appear before a prosecutor to determine whether it is for personal use. The easiest way to avoid any drug-related problems is not to use them. As of June 2017, the medicinal use of marijuana is legal.

It’s against Mexican law to take any firearm or ammunition into the country (even unintentionally).

Police corruption is a big problem in Mexico. If confronted by police soliciting bribes for bogus driving offences, you can either pretend to speak no Spanish, or else hand over photocopies of your legal documents (not the documents themselves), ask for their names and badge numbers and call their bluff by offering to accompany them to the police station.

Useful warnings on Mexican law are found on the website of the US State Department (http://travel.state.gov).