Jake, this is the questionable conduct, taken from the article Roland links to:

But after the shooting, a source inside the police department told ABC News that a narcotics detective and not a homicide detective first approached Zimmerman. The detective pepppered Zimmerman with questions, the source said, rather than allow Zimmerman to tell his story. Questions can lead a witness, the source said.

Another officer corrected a witness after she told him that she heard the teen cry for help.
The officer told the witness, a long-time teacher, it was Zimmerman who cried for help, said the witness. ABC News has spoken to the teacher and she confirmed that the officer corrected her when she said she heard the teenager shout for help.