He is in a mental hospital

"We finally found him?" Jiang Yue uttered more to herself as she was still in disbelief. 

Sunshine who heard her words, nodded, "Yes! I saw him myself and he looks the same with the photo you've shown me, so there's no doubt about it. He was just skinnier this time and, of course, older."

Feng De was the only other clue that Jiang Yue have that could lead her to the person who is responsible for harming her family and her brother.

He was the only person that Ying Wei had ever tried to meet several times, other than her, Jiang Xiu, their father, and Mao Shi. 

And most of the time they met, it was covertly, and the two avoided being captured on any kind of surveillance camera. If Jiang Yue weren't able to notice the pattern of her brother when he leaves his house, she doubts she would even be able to find out about this person.