From, this prompt what is the legal issue?

Use the IRAC method

The police in Trojan City, California, respond to multiple 911 calls about a drunken brawl on the lawn of a frat house near Trojan University after a raucous party. Upon arrival, the fight breaks up, and multiple participants flee the scene. Officer Harris chases Joe Jefferson, who she observed beating a man with a metal baseball bat. Joe is stumbling and appears drunk. After running for a block, he trips on the curb and--while falling on the ground--whacks himself on the head with the bat. When Officer Harris catches up, Joe is still conscious but dazed and slurring his speech. Since she witnessed Joe committing battery on the frat house lawn, she puts him in handcuffs and begins to read him his Miranda rights. She calls for medical assistance and asks whether he has any weapons on him.

Joe won't answer her and keeps mumbling about how he has somewhere to be, and someone will be coming to get him. Officer Harris searches Joe's pocket to find an iPhone, a half-smoked joint, and keys. Office Harris looks at Joe's phone screen and sees multiple missed calls and over 30 unread text messages in the last five minutes. Joe does not have his notification settings configured to hide iMessage previews, so she can read the first part of each text and deduces that these are contacts seeking to buy drugs from Joe. She holds Joe's phone up to his face to unlock it and searches through Joe's phone. She finds his address and more information about his drug dealing.

Later that night, police use the information from the phone to get a warrant to raid Joe's apartment. They find thousands of dollars' worth of cocaine, fentanyl, and guns without serial numbers. They also find evidence that Joe is in a gang. A judge charges Joe with assault for the attack Officer Harris witnessed, plus multiple drug charges and possession of illegal firearms--all with a gang enhancement. Joe's attorney moves to suppress the evidence obtained from his phone and apartment search warrant, alleging it was obtained via an illegal search and seizure.

Are the charges obtained from information in Joe's phone unconstitutional? Analyze under the Supreme Court's decision in Riley v. California. Do not apply any other cases or statutes when analyzing the question.