Context: In recent times, there has been increasing interest surrounding ethics within computer science. Ethical issues such as privacy, transparency, and fairness have surfaced, yet their integration into the software development lifecycle (SDLC) remains unclear. There is currently no comprehensive literature review that focuses more broadly on ethics within the SDLC. Objective: This paper elucidates the current state of the art of ethics within software development. It seeks to poke into usual ethical dilemmas and examine the stages of the SDLC where they are addressed. Method: Employs a Systematic Mapping Study (SMS) to evaluate research published across five databases to address four key research questions. Results: Our selection comprised 66 studies. Most studies (47%) concentrated on the software requirements phase within the SDLC. Over 80 distinct ethical issues were identified and organized into seven categories. Conclusion: The bulk of the selected studies focus on software requirements. While these studies articulate ethical concerns and transform them into requirements, they often fall short in proposing viable methods to integrate these requirements throughout the entire SDLC.