How loud is a 22 pistol?

Okay this is the deal, a good friend shot himself in the head on his porch at 2am yesterday morning. Now that is not like him, however people do random crazy things. Now new information I am hearing is just not adding up. First he wanted his ex girlfreind and mother of his kids back. He has been wanting this. Supposedly he asked her to marry him that very night and she said no, then he ate taco bell, laughed with his sister who he lived with, then walked onto the porch and shot himself. Now I found out while everyone was in ICU yesterday, that the trailor they live in was broken into and things scattered and here almost 2 days later they find a note he wrote saying his sister hated him. They were the closest ever and this letter did not even look like something he would write at all, not even the style of writing. At ICU the ex was not crying until way later when all the family started coming in which was weird. Now we learned that he snuck off with her and then got home and finished his taco bell within 5 mins and was laughing with his sister, then walked out and sent a mass text to everyone love you and im sorry then shot himself all within the same minute. The ex never mentioned she was with him. Now the ex has a bf who is a police officer in the same town that he was shot in who is very cocky. Im wondering if he got tired of our friend asking to get back with her, or maybe found out she came in visited him. Of course she did every payday and dragged him along. Now one big question is, the neighbor that lives 2 houses down across the street was on his porch and said he heard nothing. He shot himself 5 feet away from the trailor which has thin walls where people were, and no one heard the shot. The grandpa said oh he used a 22? Explains why no one heard. I am no gun expert and I own a 22 darringer and it is so loud your ears will ring for an hour. What other 22's are out there? I know there are more, and would any of them be quiet enough for the people that were as close to this event as they were not even hear anything? All of these things make me wonder if he got set up and perhaps someone had a silencer? Perhaps a police officer? Also they said the gun looked to be in pieces, as the sister that found him said the butt of the gun was on his stomach? What gun will fall apart? Perhaps an attempt to make it more work for someone to reshoot it for forensics? However I am assum9ng the police wrapped this right up as a suicide because the few hours later at ICU with 30 people now there, no one came to question anyone on if he said anything etc. I would imagine if they were investigating they would have come there to ask the masses! So if they wrapped it right up im sure they didnt check his hand for gun powder residue, and they just harvested his organs today at 3 and perhaps he has been cleaned and nothing will be left on his hands at this time. Well sorry this was so long but this is all not adding up. My main question is would it be possible for no one to hear this given their proximities? Also any other thoughts on all of this are welcomed. This wasnt like our friend "Mr. Smiles" but we accepted people do crazy things especially in love, however this is getting more confusing and things just do not seem right!