Is it legal in NJ for an officer or detective to work on a case where their family member was a victim?

If a person was assulted could their father work on their case as an investigator. The person's father is a officer or a detective and he has been working on this assult case. I want to know is this legal.Is it legal in NJ for an officer or detective to work on a case where their family member was a victim?
Yes and eventually it will catch up with the officer. Some detail will come to the attention of the department or the states attorney's office will do a background search and the officer's name will pop up. Then the office of professional standards will be notified and a probably good officer will jeopardize his career with revenge. The officer can do some investigating if it is kept above board and known but still the other party will question his impartiality in court. Better to give any and all information over to someone else for investigating.Is it legal in NJ for an officer or detective to work on a case where their family member was a victim?
I'm sure it's not illegal. The department may not recommend it, but i doubt there are any laws.
I seriously doubt if it is illegal anywhere. It is probably against police policy and procedure, but that is not the same as being illegal.
They can not anywhere, it is like a conflict of interest.