Due to the complexities of race and politics in this country your idea could have the opposite effect. Two specific examples come to mind:
The multiple successful fundraising efforts by George Zimmerman. (Not sure of the legalities of citizens arrest but I believe he was effectively acting as law enforcement as a neighborhood watch member)
A recent FOP (Fratenal Order of Police) fundraiser in Philadelphia for a officer who had been fired for shooting an unarmed man in the back.
There is a significant population of people in this country who will support police either because they believe the victim should have been killed regardless of circumstances or simply because they blindly support the police and always give them the benefit of the doubt
It's definitely not much, but having the first google result for someones name point to a dossier with ideally:
* Name, DoB
* Some decent photos for easy identification
* Footage of them murdering someone, pages like this without solid evidence don't seem like a good thing.
* Collection of news articles, court documents
* Contact information (social media, home address(es), phone numbers)
* Employers contact information
it's not nothing.
Hopefully it'll at least hurt their future employment prospects a little, maybe make it harder for them to find a place to rent. At the very least it'll be easier for their neighbors to find out that they're living next to a killer.
Best case scenario they'll waste a lot of their time and money trying to get the site taken down via legal means. From experience I would expect many of these folks to drive themselves crazy trying to do that, generating further source material and drawing even more attention to their past.
The somewhat unlikely worst case scenario is that it simply doesn't bother them at all.
Maybe the courts wont punish them, but it shouldn’t be very hard to ensure that the label of MURDERER will follow them for life.