The only thing stopping police from figuring out what happened on Monday between George Zimmerman and his estranged wife, Shellie Zimmerman, is an iPad that was smashed into "multiple pieces" during the alleged incident. It was George Zimmerman who did the smashing, of course. 

An altercation erupted Monday between Zimmerman, Shellie, and her father, David Dean. The details are sketchy, but this is what we know. Shellie Zimmerman told 911 dispatchers that Zimmerman punched her father in the nose, that he was brandishing his gun, that he pulled a knife on her and smashed her iPad. Here's the 911 call: 

Just days before, Shellie Zimmerman announced she was filing for divorce. But Shellie Zimmerman and David Dean both decided not to press charges. He was free to go, again, and the police never did find the gun. At first it seemed someone was lying about the gun after Shellie Zimmerman's story changed Monday evening. But Lake Mary police kept investigating, attempting to piece together what happened the best they could from witness statements and security camera footage.

The investigation is now focussing on the smashed iPad because Shellie was allegedly filming the incident before Zimmerman smashed it to pieces, Lake Mary police spokesman Officer Zach Hudson announced Tuesday, per the Associated Press

“The iPad video is going to be paramount in this case,” Hudson said.

When asked who could possibly be charged, Hudson said, “As of right now, it could be either one or it could be no one. It depends what that iPad has on it, what that footage shows.”

Since the incident happened, both have accused the other of being the aggressor in the incident. Zimmerman says his wife pushed him, and his now former lawyer Mark O'Mara said the incident was nothing more than a common domestic dispute between soon-to-be-divorcees. But police are looking at charging Zimmerman with domestic violence if they can recover the video on the smashed iPad. In Florida, the state attorney doesn't need a victim's consent to charge someone for domestic violence. Zimmerman could also be charged with destruction of evidence, depending on what the iPad reveals. "It's been pretty badly damaged," Hudson told reporters, about the iPad.

The phantom gun has also completely disappeared. "We searched him... there was no weapon," Hudson said. "As of right now, a gun is not a part of the equation." Where the gun went, well, we'll probably never know.