they pleaded with officers, who were assembling outside the school, to enter the building

[GoodTaste]

But none of the extensive preparations halted the rampage of an 18-year-old gunman who entered a Uvalde elementary school this week and killed 19 children and two teachers. Family members who had rushed to the scene said they pleaded with officers, who were assembling outside the school, to enter the building.

Source: NYTimes

Who are the subject of the verb 'enter' here? Officers or family members? Both could have guns to fight the gunman. On second thought, I think it is officers. Because if it was the members, it would be written as "to be allowed to enter". The problem is of logic, why didn‘t the officers enter the school to stop the violence? The confusion of the logic leads to the confusion of understanding the grammar.

 

[emsr2d2]

Family members who had rushed to the scene said they pleaded with officers , who were assembling outside the school, to enter the building.

Does the above help? You're right that it refers to officers.

As far as I can tell from the news reports so far in the UK, there is some confusion around how long it took police to enter the building but there do appear to be quite a few reports of members of the public (mostly the parents of children inside the school) saying that there was a long delay, that they were urging police to enter faster and, in some cases, planning to go into the building themselves if the police didn't act.