The end-of-1998 review found that there were 303 (2.4 percent) offenders aged 18 to 20 years, 1,314 (10.3 percent) offenders aged 21 to 24 years, 9,535 (74.7 percent) offenders aged 25 to 49 years, and 1,606 (12.6 percent) offenders aged 50 and over in Federal institutions. There were 47 (0.5 percent) offenders aged 18 to 20, 686 (7.1 percent) offenders aged 21 to 24 years, 6,979 (72 percent) offenders aged 25 to 49, and 1,977 (20.4 percent) offenders aged 50 and over on conditional release. Overall, in Federal corrections young adult offenders are turning over at the greatest rate in institutions and on conditional release. They also are serving shorter sentences, are likely to be robbery offenders, have more criminal history as youths, and have unique criminogenic needs at admission and on conditional release. These findings suggest offering specialized programs and services to these offenders, and careful attention should be paid to them during reintegration. 7 tables and 5 footnotes The study was conducted in rural and urban areas of central California. Data were collected through a self-report survey of 4,000 Mexican households characterized by low-income and low education. The survey solicited information on the carrying of a weapon within the last 30 days, arrests, fighting, life-time drug use, and drug abuse and dependence. On all measures of deviant and criminal behavior, the study found that Mexican immigrants reported less involvement in weapon-carrying, arrests, fighting, and drug use and abuse than American-born Mexicans. American-born Mexican males reported 150 percent more weapon-carrying, 100 percent more fighting, 100 percent higher drug use, and 300 percent higher drug abuse and dependence. American-born female Mexicans were 700 times more likely to have used drugs and 100 times more likely to have abused drugs than immigrant Mexican women. Evidence of change over time in the immigrant population was determined by surveys of immigrants who had been in America less than 14 years and immigrants who had been in America more than 14 years. There were clear signs of increases on all measures of crime and deviance over time among immigrants. Approximately one-half of the arrests for immigrants were for drunk driving. The study supports the view that Mexican immigrants are assimilated into the higher crime rates of American-born Mexicans. The study recommends focusing on improving school performance and academic achievement for Mexican immigrants, so they may participate in economic mobility and assimilation into the economic and social mainstream of American life. As long as immigrants are trapped in low-income, high-crime neighborhoods, they will be prone to crime and drug abuse. Questions and answers follow the presentation.