It appears that your question is whether a cop can sit and run a speed trap without their car lights on. If this is your question, the answer is Yes. Good luck.
This information is offered for informational purposes only, as I do not practice law in your State. It is not intended as legal advice and you should not rely upon it to decide how to resolve this issue. No Attorney-Client relationship is intended or established by this response.
Yes, the police doesn't need to have their lights on.
Attorney Jason Chan
77 Franklin Street, FL3
Boston, MA 02110
disclaimer: I am not licensed to practice law in your state. Please be aware that this is for informational purposes only.