(RNS) — It may be a law of nature: President Trump tweets something about Islam. Anti-Muslim hate crimes follow.

That’s according to a working paper by University of Warwick researchers Karsten Müller and Carlo Schwarz.

Their conclusions correspond with anecdotal reports collected by Muslim civil rights and advocacy groups, too.

“Whether it’s a tweet or whether it’s in a policy (Trump is) introducing, or if it’s in a policy someone in his administration is introducing, I think it all comes together to create this kind of environment where targeting Muslims is acceptable or has become acceptable,” said Madihha Ahussain, special counsel for anti-Muslim bigotry at Muslim Advocates.

Müller and Schwarz examined publicly accessible data such as the weekly number of anti-Muslim hate crimes recorded by the FBI in their paper, “Making America Hate Again? Twitter and Hate Crime Under Trump.”

The data showed a rise in anti-Muslim hate crimes since the start of Trump’s presidential campaign, concentrated in counties with high Twitter usage. It also showed a correlation between the number of Trump’s tweets in a given week that used keywords related to Islam and the number of anti-Muslim hate crimes that followed.