[Grammar] problem with tenses

[angelene001]

Can the past continuous be used here?

The security guards were standing by the door and they were checking everyone before they entered the building.

Or the only option here is the past simple:
The security guards stood by the door and they checked everyone before they entered the building.

 

[5jj]

They are both possible, but they do not mean exactly the same.

 

[Tdol]

You could also mix the two forms and slightly alter the meaning.