Montgomery County's top prosecutor John McCarthy described an attack so brutal that even cops who've seen it all couldn't comprehend. A woman has been charged with killing her colleague inside a Bethesda yoga store and then hurting herself to trick police into thinking she too was a victim.

That's how what was at first thought to be a random crime became an inside job, police and prosecutors said during Monday's court hearing for the prime suspect. The Washington Post details the hearing:

McCarthy said the attack in the store occurred after closing March 11, shortly after Murray reported to a manager that she had discovered stolen store merchandise inside Norwood’s bag. Norwood bludgeoned Murray for as long as 20 minutes and struck so many blows in the same places on her body that it was difficult to determine the exact number of wounds, the prosecutor said.

“The nature of this crime is shocking in terms of the level of violence,” McCarthy told the judge. “The majority of the blows were directed at [Murray’s] head. Her skull was crushed during the attack.”