My brother's behavior outbursts are puzzling the entire family. Can you help?

Hi doctor,

I am 23 and the oldest of thirteen kids. My little brother, who is 15 years old, has struggled with depression and is suicidal, or so he claims. He has always been normal around me, and I have never seen any signs of this, but I moved out about five years ago. He once took a knife and held it in front of his wrists, but he has been doing all kinds of things, and a family advisor said he was being manipulative and bluffing and to call him out on it. So, my mom did so and said go ahead and kill yourself, but just know the hurt you will cause and you will end up in hell. He then dropped the knife and did not do anything. Recently, things have been getting out of control. He had crashed the family suburban, taken a handful of Ibuprofen pills, threatened to kill himself, and attacked my mom when she said he could not go out with his friends. When the cop came, he started swearing at him, trying to get arrested, which the cop would not do. It got worse until the cop came back and took him away to a correctional facility. My mom said he has wanted to go to a boy’s home since he was about in fourth grade, and the doctors say he does not have bipolar, but he just hates authority and cannot take no for an answer when he wants to hang out with friends or have a smartphone. At work and school, he has been fine, and people love him, but he has sudden outbursts that are just puzzling. My question is, why would he want to go to a boy’s home/correctional facility? This makes absolutely no sense to anyone in the family. The family has no history of anyone having gotten in trouble which makes it all the more strange. Any input on this is appreciated.