Mystery Monday: Conviction

Some perp walk photos showed up on the web,
And then Mariah showed up late to work
With ink-strained fingertips. When nosy Deb
Asked if she could be helpful, just a smirk
Was her reply. What had this woman done?
This sweet, enthusiastic employee,
Who'd always taken bullying (good fun,
They'd always claimed, but sometimes things could be
A little cruel), what mischief had she wrought?
The internet, the TV news, all kept
The secret. At what misdeed was she caught?
The office rumors went wild, 'til she wept
And went home early. Later, she resigned,
Not telling she'd been witness to a crime.