Traces (BritBox)

This British mystery series has an intricate plot, revolving around a young woman named Emma who moves back to her childhood hometown in Scotland to take on a job as a forensic assistant. She's encouraged to do an online course that covers the fictional case of a body that has been found, but is shocked when it bears many similarities to her mother's own unsolved murder 18 years earlier. That sets a wave of events in motion that eventually puts a number of people in danger, including Emma, as she sets out to solve her mother's murder.