Can a lecturer or professor mark a few lates as an absence?

I know a professor can count a late as an absent if a student misses roll call. But can a professor mark a few late as one absent(which day would they mark it as). Or can they lock the door and disallow late students to enter? Which my professor did. Is it one thing to mark a late as an absence and another to make the student who's late physically absent? Especially when the college handbook allows professors fail students after exceeding some percentage of absences. This professor is withdrawing for absences not exceedpercentage & for lates they marked as absent because students didn't see them after class. I don't recall them saying 'stay after class' nor is it on their syllabus but they said they did. Their rules remind me of HS, especially the confiscating cellphones for a whole semester if a student repeatedly pulls it out/doesnt shut it off.