Determinations for whether migrant families that have been taken into federal custody for illegally crossing the southern border are sent back to Mexico or released into the United States are more luck than anything else.

A senior Border Patrol official disclosed Friday that his agents decide each family’s fate based on a myriad of factors that can change at a moment’s notice and affect whether someone is able to claim asylum or is instead flown away. It comes down to how many are in its custody up and down the border, if Immigration and Customs Enforcement has room to take in families, and a plethora of other factors. Regardless of the circumstances prompting families to travel for weeks to get to the border, all are treated the same.