Thanks for your replies.
I guess I'll just follow them for a bit after we clear the light to pull them over. Like some of you said, it's not realistic to pull them over at the intersection.
Whenever I try to attempt a traffic stop at a traffic light with other cars around, the car I'm pulling over has no where to go because everyone else has stopped because my lights are on. Is there anyway to make other traffic ignore my lights when pulling someone over?