The "secure" thing for the LEO is for them to have control of any and all firearms in responding to a complaint.
Scenario 1: Husband and wife are arguing. Neighbor complains to LEO. LEO responds and finds that husband has a firearm in his holster on his side. Normal response to a domestic disturbance complaint is that it could escalate to something bigger. First LEO action is to disarm husband.
Scenario 2: Complaint made of "Man with a gun". LEO responds. Does LEO know the man's intentions? No, so disarm, then discuss. If man has nothing to worry about, man will comply. If man is up to no good, then man tries not to comply.
Scenario 3: LEO observes lady doing a traffic violation. LEO follows lady then turns on the lights. Lady pulls over. If lady did not pull over, then suspicion takes over that lady is up to no good and "flight = guilty" of something.
Securing a scene of firearms is for most LEO's standard procedure. They do not want things to escalate to a level where firearms could be used.
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
Life Member NRA
Life Member NAHC
Former President of the ECPT (Eifel Combat Pistol Team)