Carl knew that you SH...he knew you too well,even when you started to act like there was nothing wrong,like you have actually stopped, he never believed you.

he could see through your bullshit.

he never checked your wrists,he didn't need to,he already knew that they were going to be clean,unless for some old scars...he knew that your thighs were getting it all.

Ron asked him if you had stopped and Carl looked at him in the eyes and said

"she never really quit she just says she did"