I am looking for the name of an old movie. I am not sure if it was black and white... although, I believe that it was. There is a scene (I think it is the end) where the main character (male) is holding the "creature" baby. He is standing in the opening of a tunnel - like an old sewer tunnel, maybe. He is surrounded by police and maybe scientists... they want the baby to kill it. He is insisting that it is just an innocent baby - the audience can hear the "baby" crying... It is driving me CRAZY!! I can picture the scene, vividly, but cannot place the movie.

Thanks for any help you can offer!!

Think you're looking for 'It's Alive'.
Here's a snippet of the plot that matches your description:
The police contact Frank and inform him that the child has been tracked to the sewers. Frank takes a rifle into the sewer to hunt the infant. While in the sewer, Frank catches sight of the child and leaves as the cops continue searching. As Frank nears the child, he realizes that the child is simply frightened and will not hurt him. He apologizes for hurting the child, and picks up the crying infant...
It's Alive (1974) - IMDb

That sounds like it could be it!! THANKS!! You are a RockStar!!

Yay! :)