The Department of Homeland Security began separating migrant families at the border in 2018 despite knowing it did not have a sufficient way to track and reunite the thousands of affected people, according to a new government watchdog report.

The DHS inspector general’s office report released Wednesday said then-Secretary Kirstjen Nielsen’s department misreported the number of split-up families, and the decision to implement the policy did not lead to a decline in illegal crossings of families as the Trump administration had claimed would happen.