In the Blink of an Eye by Jo Callaghan

In this series launch, a police detective is asked to lead a pilot program examining cold cases with the help of an Artificially Intelligent Detective Entity (AIDE) – basically, a robot – as part of her team, with results that surprise her. Detective Chief Superintendent Kat Frank has been on leave while recovering from the death of her husband and resulting depression of her teenage son but now she wants to return to work.