Darnell Gates, 30, walks on his block in Philadelphia, Pa., on Oct. 3, 2019. Gates, who is on probation in Philadelphia, was deemed “high risk” by a computer algorithm, one of many that governments are using to decide how people should be treated. Across the United States and Europe, software is making probation decisions and predicting whether teens will commit crime. Opponents want more human oversight. (Jessica Kourkounis/The New York Times)