This study was conducted to examine whether a rising crime rate in El Paso, Texas and San Diego, California in 1986 could be attributed to, among other factors, the influx of undocumented aliens. Variables include level of involvement of undocumented aliens in serious felony arrests in San Diego and El Paso Counties, the outcome of serious felony arrest cases involving undocumented persons compared to others arrested for similar offenses, the impact of arrests of undocumented aliens on the criminal justice system in terms of workload and cost, the extent that criminal justice agencies coordinate their efforts to apprehend and process undocumented aliens who have committed serious crimes in San Diego and El Paso counties, and how differences in agency objectives impede or enhance coordination. Data are also provided on how many undocumented persons were arrested/convicted for repeat offense in these counties and which type of policies or procedures could be implemented in criminal justice agencies to address the issue of crimes committed by undocumented aliens. Data were collected in the two cities with focus on serious felony offenses. The collection includes sociodemographic characteristics, citizenship status, current arrest, case disposition, and prior criminal history with additional data from San Diego to compute the costs involving undocumented aliens.

The border city of Tijuana was the Mexican municipality with the highest number of homicides, with 1,844 cases reported in 2023, a decrease when compared to the over 2,000 cases reported last year. Tijuana was followed by Ciudad Juárez, located south of El Paso, Texas, with a total of 1,246 homicides.

The project was divided into two studies that together sought to compare criminal histories and victimization experiences for immigrants compared to U.S.-born citizens in the U.S.-México border region. Study one (datasets 1 and 2) of the project consists of secondary data from the El Paso County Sheriff's office, the US Census, and the El Paso Neighborhood Survey. Study two (dataset 3) of the project consists of interviews with inmates from El Paso county jails.

This data collection investigates the ways in which police use reports of drug-related crimes provided by residents of high drug/crime areas and how willing residents of these areas are to report such crimes to the police. Structured interviews were conducted by telephone with police representatives in most of the nation's 50 largest cities and in person with residents and police officers in high drug/crime districts in each of four major cities: Newark, Chicago, El Paso, and Philadelphia. Police department representatives were queried about the usefulness of citizen reports, reasons for citizens' reluctance to make reports, how the rate of citizen reports could be improved, and how citizen reports worked with other community crime prevention strategies. Residents were asked about their tenure in the neighborhood, attitudes toward the quality of life in the neighborhood, major social problems facing the neighborhood, and quality of city services such as police and fire protection, garbage collection, and public health services. Additional questions were asked about the amount of crime in the neighborhood, the amount of drug use and drug-related crime, and the fear of crime. Basic demographic information such as sex, race, and language in which the interview was conducted is also provided.