Why Isn't the LAPD Investigating Charlie Sheen?

Charlie Sheen proved he is as erratic as they come during his media meltdown tour, and he reputedly even turned violent toward ex-wife Brooke Mueller during an altercation in the Bahamas. And since this is Sheen we're talking about, this dispute wasn't your typical marital spat; it reportedly involved threats of beheading and a penknife to the eye from Charlie.
So what's stopping the LAPD from investigating?
MORE: What would it take for Charlie to lose his kids for good?
Brooke has filed a temporary restraining order (TRO), but that's not enough to bring in law enforcement.  "We cannot act on a report in her TRO," LAPD Officer Norma Eisenman tells us. "Unless she comes in and does a report, we can't do anything."
Despite the very violent nature of the threats mentioned in the TRO, Eisenman still insists that Sheen's ex-wife will have to take further action. "She has to file a crime report," she says.
Sources close to Mueller have repeatedly told E! News that she hopes to reach some kind of a deal with Sheen and won't be getting the cops involved. A court hearing on the TRO is set for March 22.
—Additional reporting by Marcus Mulick
VIDEO: The Soup: Charlie Sheen's Guide to Duh, Winning