Mexicali has very low crime rates, not just compared to other Mexican cities, but even compared to American cities.

Their murder rate is comparable to Wichita Kansas. You are 20 times less likely to be a victim of theft than in the US.

Mexicali has a population of about 1 million people. They spend quite a bit on education, have a substantial middle class, and low unemployment rates.

Obviously be cautious, just like you would be in any city, but no reason to be paranoid.

I sure hope there is no one that decided not to go because of fear of crime.