The leader of the Foot Clan was purportedly called Shredder. He also had a Japanese foster daughter called Karai. The father and daughter were the leaders of the gang.
But the little turtles had been fighting the Foot Clan for a while, and had never seen Shredder. They had only seen Karai twice.
In the blink of an eye, three days passed, and the two were still nowhere to be seen. There were no unusual movements from the Foot Clan either.
On the other hand, Sacks had mobilized a group of people, presumably to catch the little turtles.
These people were from the Foot Clan; they weren't hoodlums who peddled drugs, but professional combatants.
Luke didn't make a move against them.
The more active they were, the more clues there would be.
April was still idling in the dark room. It would be hard for the Foot Clan to deal with the little turtles without a hostage.