Help! Blanking on 70s New York movie with bad child actor.

Hi.  I'm looking for the name of this film please - pretty sure it was 70s, pretty sure it was New York, the plot was I think about a lady cop or DA looking after a street kid.  From memory, the piece that took me to it reckoned the actress was terrific, but the child actor performance was notoriously dreadful.

The scene I saw was set maybe upper Manhattan or in the Bronx.  The cop/DA comes out of her office, runs into the street kid (I think he was hispanic), she tells him she can't help him and he should go home or get lost (maybe he's an informant?), a car drives by with men in it who shout out to the kid, the woman gets a bad feeling and tells the kid to get in her car and they quickly drive off.

I feel like it should be a famous movie, but I just can't place it.  Any ideas?