Division officers or detective or the 9th Mobile could get some information that way. Collecting high value intelligence requires establishing a long-term rapport and a level of trust requiring a high degree of experience and resources. They don't want their names in any reports that could be subpoenaed by a defense attorney. They don't trust 99% of police to keep their names from those who'd likely kill them. Detroit has very good gang intelligence officers who don't look, talk or act like police.