Trump has once again put The U.S. on the world stage this time at the expense of innocent children whose families are seeking asylum. The Trump administration’s justification is that:

I decided to try to analyze this statement quantitatively. Indeed, one can calculate the probability that an illegal immigrant will commit a crime *within* The United States as follows. Let us denote crime (or criminal) by *C*, while denoting illegal immigrant by *ii*. Then, by Bayes’ theorem, we have:

It is quite easy to find data associated with the various factors in this formula. For example, one finds that

Putting all of this together, we find that:

That is, the probability that an illegal immigrant will commit a crime (of any type) while in The United States is a very low 11.35%.

Therefore, Trump’s claim of “tremendous amounts of crime” being brought to The United States by illegal immigrants is incorrect.

Note that, the numerical factors used above were obtained from:

- https://www.justice.gov/opa/pr/departments-justice-and-homeland-security-release-data-incarcerated-aliens-94-percent-all
- https://www.washingtontimes.com/news/2017/aug/1/immigrants-22-percent-federal-prison-population/
- https://en.wikipedia.org/wiki/Incarceration_in_the_United_States