The facts of the Root case were never in dispute even as Democrats and others challenged some of Mr. Trump’s statements against illegal immigration.

For example, PolitiFact rated as “half true” his Oct. 27 declaration: “Thousands of Americans have been killed by illegal aliens.”

“In reality, there is no solid data for homicides committed by people here illegally,” PolitiFact said in a Nov. 3 analysis. “His implicit suggestion is that people should fear illegal immigrants more than citizens, and we don’t see evidence for that.”
Yes, there is. There's data all over the place, in every homicide in America, except unsolved cases, the who died and who done it is in a database. Every citizen can be verified, every immigrant can be verified, everyone else is an illegal alien. The solid data is there for any reporter or "Fact checker" willing to report it.

It's not just "thousands" who have been killed, it's TENS OF THOUSANDS. It's thousands every year. Probably close to 100,000 or more by now.