Did you listen to the audio? The person calling 911 was the supposed suspect he claimed to have killed his father, so I'm not sure how you would contact the suspect without just getting the same 'prankster' again.

Knocking on doors of the neighbors sounds great, but does it give you any useful information if no one heard a gun shot? What if he shot his dad in the basement, or the walls of the house are thick enough to block the sound. You still need to go in and check even if every neighbor said they didn't hear anything. Also, knocking on doors wastes what may be valuable time in a real hostage situation.

Calling the house won't get the "prankster" again. If you call the house and the same person answers making the same threats, that's confirmation that the situation appears to be serious (most likely someone attempting suicide by cop though).

If the person who answers tells you that nothing is wrong, and that no one called the cops, then swat team can be a bit more careful about keeping their safeties on.

I still don’t see how calling a phone number associated with that address and seeing who picks up could hurt anything.

This phone call could’ve occurred while SWAT was deploying to the scene.

They only could’ve gained by doing this.

If it was real, and the hostage taker picked up, he could say everything was fine. What do you do then? Calling seems like a good idea but I'm not sure it provides any actionable information.

You're making an amazing effort to dream up new worst-case scenarios that could justify the speediest, least hesitant response. Great imagination and creativity, but you're violating Occam's razor by multiplying entities, ie inventing new facts to rationalize an illogical position. Yeah, maybe the murder could have taken place and the neighbors would be unaware of it because it occurred in an almost soundproof basement, but how do you know the house even has a basement?

Sure, you want to get police into position as quickly as possible, but you can also direct other people to investigate at the same time. And instead of just yelling directions at the guy from a distance when he came to the door, they could have tried asking questions when he appeared.

I mean, you can just as easily imagine other non-threatening factors. What if it was real, but the person at the door was actually one of the hostages who had been released but was scared and disoriented? What if it was an innocent person who was deaf? Police in Oklahoma shot a deaf guy 3 months ago even though people were yelling at the officers to tell them he was deaf. Police know what swatting is, and it's a common enough term that newscasters can use it in a sentence these days, so why didn't they consider that possibility?

I realize you're trying to be objective, but almost every one of your posts on this subject actually depends on a logical fallacy.

I said the police could only have gained from calling. You have not provided a scenario in which it would further endanger lives. Even if it didn’t provide “actionable” info, it wouldn’t hurt to try and some semblance of doubt around the veracity of the initial claims could be forwarded onto the SWAT team.

Then you tell your team there is a high likeylhood of a false call, and maybe they don't keep their fingers on hair triggers.

In this case, the supposed hostage taker was the 911 caller.