No comment...
The desecration of this mural has been a years long issue, you can see the repeated cleaning and re-paining that's been performed on the lower 8 feet of the painting, and the large tags didn't appear this week, they were there in January when I passed by it.
Someone's smart enough to use the Memorial Day weekend to bring attention to the mural, and hopefully get it back to a memorial rather than a community eyesore.
As for investigating; LAPD takes pictures of graffiti, stores it in a database, then revisits the site and may cite the property owner if the graffiti hasn't been removed.