In Suicide Squad Vol 4 #1 (New 52):
After a falling out with the Joker, she goes into a murderous frenzy,
directed towards people responsible for the Joker's imprisonment.
Captured by Black Canary, she is forcibly inducted into the Suicide
Squad by Amanda Waller. However, when she discovers that the Joker
is rumored to be dead, it takes a further toll in her already addled
mind, and betraying the Suicide Squad, she puts their safety and
secrecy at risk by turning herself into the Gotham Police Department
in a plot to gain access to the skinned face of the Joker.(Vol 4#6)............
(Source: Wikipedia, dc.wikia.com/ (1,2)