Criminological research frequently involves the obtaining of data from persons who could be criminally prosecuted based on the information given to researchers. Although researchers may not be legally immune from revealing their sources and producing research information deemed confidential by the researchers, the ethical commitment of the researcher should be to those who have provided the research data with the understanding that no adverse consequences would attend their participation. Whether a research staff is immune from contempt for failure to submit files to examination or impounding upon a court order is undecided in case law. Should such an occasion arise, litigation to protect the names of its sources should be pursued by the researchers. Researchers are often called to testify in court to reveal scientific findings that have relevance to an issue before the court (e.g., whether discrimination is prevalent in the application of the death penalty in particular States). Researchers should particpate in such proceedings, even though the presentation of findings may be abused or distorted by persons involved in the case. As probability statistics have become increasingly admitted into litigation, some judges have come to accept the P value of .05 as nearly sacred in determining what is acceptable science. Neither scientists nor judges should be so wedded to the .05 notion as to ignore consistent patterns of P values a bit more than .05. Regarding the ethical dilemmas likely to attend receipt of research funds from various sources, the researcher should be particularly careful that study findings are not slanted to cater to the self-intererst of the sponsor. In teaching criminology, it is the obligation of the teacher to make clear to students to particular biases that influence the perspectives the teacher presents in class. Footnotes are provided.