SPRINGFIELD, Mo. — Twenty people accused of distributing heroin and fentanyl in Springfield are now off the streets.

That’s the word from federal prosecutors after a months-long investigation that involved multiple agencies.

This is what we know about the investigation: Drug investigators launched the effort back in June.

Investigators made undercover drug purchases and seized drugs and cash.

They say the heroin and fentanyl came to Springfield from suppliers in Chicago and St Louis.

Most of the people charged were arrested late last week.

One month ago, dozens of people overdosed, and several people died in Springfield.

Authorities have not said whether any of the people facing federal charges, sold the drugs involved in that wave of overdoses.