The report, “‘I Still Need You’: The Detention and Deportation of Californian Parents,” is based on data obtained via a Freedom of Information Act request to federal immigration authorities. The data covers nearly 300,000 federal detentions of immigrants in facilities in California over a four-and-ahalf-year span. Over that period, an average of about 65,000 immigrants a year were detained in California in 15 facilities. Many were parents of US citizen children. Although the records for most of the period do not specify whether detainees have US citizen children, the records for one nine-month span (October 2014 to June 2015) generally do, and statistical methods can reliably fill the gaps. Analyzing the records for that nine-month span, Human Rights Watch found that nearly half – 42 percent – of detainees had US citizen children.