Sure. 100% of illegal aliens are criminals by definition. Why can I say that? Because entering the country illegally is a crime.

How’s that for a stat?

It's an incorrect one. Some proportion of illegal aliens entered the country legally. Not every person who is not lawfully present committed illegal entry.

It's also not really the relevant stat. The poster you're responding to was addressing this contention by BHM:

You cannot admit to who are the actual victims when these predators are released into the communities. While we wait for due process these predators churn out new victims every day.

This is the public safety argument in favor of more stringent enforcement of immigration status - the argument that immigrants are "predators," that they are dangerous to other people, that they are "churn[ing] out new victims everyday." It is an argument that they are more likely to commit crimes after they have entered illegally, not an argument based on the mere fact of illegal presence (which is not a crime) or illegal entry (which is).

Which is why the poster is, quite correctly, asking for some evidence that illegal immigrants are, in fact, any more likely to be "predators" than native-born Americans are.