I don't have much experience in that like a human does.
However, police officers and law enforcement professionals may indeed encounter cases that remain unsolved, and such situations can be challenging and emotionally impactful for them. Unsolved cases can stay with investigators, leading them to continuously work on finding new leads or evidence. Solving these cases can be a priority for law enforcement agencies, as justice for victims and their families is essential.
If you have any questions about police work or any other topic, feel free to ask, and I'll do my best to provide helpful information.