M3P2 Data Sources

Sources and Collection

The M3P2 dataset is compiled from death reports obtained through public information requests submitted to state and county agencies along the United States–Mexico border. Primary data sources include medical examiners’ and coroners’ offices, county sheriff’s offices, and, in Texas, Justices of the Peace. In addition, the dataset incorporates one national-level source: publicly accessible unidentified persons reports from the National Missing and Unidentified Persons System (NamUs). NamUs cases were included only when the available case notes provided sufficient information to identify the decedent as a migrant. For example, a case would be included if the Case Circumstances notes stated, “Remains were recovered from a known migration corridor.”

The M3P2 dataset also incorporates data from No More Deaths, a humanitarian organization based in southern Arizona; Operation Identification, a program of the Forensic Anthropology Center at Texas State University; and the International Organization for Migration’s Missing Migrants Project. We also requested data from several other local, state, and federal agencies, including the United States Border Patrol’s Missing Migrant Program, but were unable to obtain access to their records.

Sources List

List of case data sources as of August 2026: 

  • Riverside County Sheriff’s Office, CA
  • San Diego County Medical Examiner’s Office, CA
  • Imperial County Coroner’s Office, CA
  • Maricopa County Office of the Medical Examiner, AZ
  • Pima County Office of the Medical Examiner/Humane Borders’ Open GIS of Migrant Mortality, AZ
  • No More Deaths, AZ
  • New Mexico Office of the Medical Investigator, NM
  • Brooks County Sheriff’s Office, TX
  • El Paso County Office of the Medical Examiner, TX
  • Hudspeth Justice of the Peace 1, TX
  • Hudspeth Justice of the Peace 2, TX
  • Operation Identification, Texas State University, TX
  • Publicly accessible NamUs unidentified persons reports, TX and CA
  • International Organization for Migration (IOM) Missing Migrants Project (MMP)
     

See our full M3P2 Methodology for more information on our data collection. preparation, scope, and limitations.