Originally Posted by Acid Erosion88
I was havin' trouble with this so just carried on with other missions. Picked up the item for Growing Pains without even realising it until I went to turn in other missions. I think it might be zombies that are electric for too long go supercharged but I can't confirm it.
Use the sonic status effect, its Rachels character weapon or any weapon mixed with sonic loot drops.
Police cars give off same effect.