NEWARK, N.J. (AP/KRQE) – Nine people in four states are facing charges for their alleged roles an interstate dog-fighting ring.

The charges announced Wednesday by federal prosecutors in New Jersey stem from an undercover investigation.

Authorities say the ring has operated since last October. Six of the people charged are from New Jersey, while the others are from Illinois, Indiana and New Mexico.

Eight of the suspects were in custody as of Wednesday afternoon. Each person charged could face several years in prison if convicted of roles in the ring.

Robert Arellano, 62, of Albuquerque is facing charges related to transporting, delivering, buying, selling, receiving and possessing pit bull-type dogs for dog fighting. According to a criminal complaint, Arellano

They say evidence of dog-fighting ventures – including scarred dogs and dogs stacked in crates – were found and seen on some of the defendants’ properties.

The federal Animal Welfare Act makes it a felony punishable by up to five years in prison to fight dogs or to possess, train, sell, buy, deliver, receive or transport dogs intended for use in dog fighting. If convicted, each defendant faces up to five years in prison and a $250,000 fine per count of animal fighting charges.

Officials say the investigation is ongoing.