DETROIT -

Prison -- that's where some of Detroit's most brazen gun dealers are headed to.

A federal judge is sentencing those caught in a creative sting operation. It looked like an average barbershop. However, it was really undercover agents running a sting operation.

Read back: Feds set up undercover barbershop to catch gun sellers

When word hit the streets that the barbershop was cutting hair and buying illegal weapons, sellers started lining up.

"People were just coming off the street offering to sell us guns" said one undercover ATF agent.

Video shows them bringing in hand guns, automatic weapons, some of the guns stolen. All being sold with little regard for the lives that might be taken with them.

"These operations are important due to the fact that they are able to remove the most violent offenders from the community, thus making the community safer," said David McCain, special agent in charge with ATF Detroit.

The sellers were arrested by the ATF and now the first defendants are facing federal judges. Wilfredo Betancourt got seven years in prison, Darius Longmire got four years and on Thursday afternoon Charles Williams was sentenced to three years.

Prosecutors say the investigation took multiple weapons off the street that otherwise likely would have been used in violent robberies or worse.

The barbershop now is a neighborhood store.