Factual error: Shazam catches the bus with his hands, but it lands on his hands and face by the windshield. This puts the entire weight of the bus being supported by just the front windshield held by Shazam's hands, plus the momentum of it falling from the bridge hitting him. No way the glass could support all that and not break. Especially since it already cracked from just a guy falling on it.
Factual error: When the young Sivana is arguing with his older brother in the car before the crash in 1974, the digital display on the car radio isn't accurate for that timeframe.
Answer: He was a baby when he was abandoned - all he knew about his mother was her name, not her birth date or social security number. He didn't know anything about his father and his mother went back to her maiden name. In case you're wondering not everybody has their DNA taken.
He knew his full name. He's a legitimate son born in wedlock. They would have easily tracked down the father who is an inmate: that is on top of what the original poster mentioned, such as his home address or other minimal information. Lionhead, I believe this belongs in the Plot Holes section rather than simply the Questions section: I am not informed about Pennsylvania's laws for child abandonment, but I think it's rather unlikely that someone could just drop their kid in the middle of a crowd and get away with it entirely, especially when the kid knows his own full name.
Sammo ★
I'm not too eager to put it in the plot holes section, because it is plausible I suppose that she disappeared willingly and they couldn't find her specifically. But you address the right point I was trying to make that the cops won't simply stop looking for his mother. It's a crime to abandon your child and they will look up and question a lot of people. And I mean a lot of people to find her. Even if there is literally no family besides mom and dad, the dad will be found since he is in prison. He won't be able to help much but contact will be maintained, even if he doesn't want it.
lionhead
The thing is, they don't even have to question a lot of people since the kid is not a newborn left on the steps of a church or something: he was able to provide his own full name to the authorities. So it's absolutely straightforward for the police to see who his parents are - although it should be noted that he was born in a different state, I don't think it should be a particularly complicated research for the authorities.
Sammo ★