GRAND RAPIDS, MI - Investigators busted an alleged drug-trafficking organization accused of bringing kilograms of cocaine to West Michigan.

Police used search warrants at 10 residences, mostly in the Grand Rapids area, intercepted telephone calls, reviewed toll records, conducted surveillance and used GPS trackers on cell phones and vehicles in a multi-state investigation, court records said.

The investigation began in Grand Rapids in early 2017, court records said.

Howard Anthony Mayfield, a.k.a. "G," and "Dirty," allegedly headed up the organization, which received kilograms of cocaine from Wilbert Gentry, a source in Houston, and later, from sources in Detroit and Muskegon, the government said.

Mayfield and Gentry were once locked up together in a Texas prison, Alexis Giudice, a special agent for the U.S. Drug Enforcement Administration, wrote in court records.

The DEA worked with the Metropolitan Enforcement Team in Kent County and police agencies in several states.

A 140-page criminal complaint, naming 15 suspects, was unsealed Friday, May 25, in U.S. District Court in Grand Rapids.

Giudice said Mayfield directed a drug-trafficking organization by personally bringing kilograms of cocaine here, or having others do it. He would collect money from co-conspirators to put toward bulk orders of cocaine, then pay through money-wiring services, the investigator said.

Mayfield was under investigation when an undercover officer bought cocaine and heroin from him in spring 2017, the government said.

"Throughout the course of this investigation, law enforcement has obtained search warrants for the collection of Global Positioning System ("GPS") data from GPS Tracking Devices on Mayfield's vehicle.

"Through a combination of GPS data for Mayfield's vehicle, analysis of phone records, and physical surveillance by law enforcement officers on various dates, investigators determined that Mayfield and other DTO (drug-trafficking organization) members made short trips from Grand Rapids to West Memphis, Arkansas, and Houston, Texas, on numerous occasions since October 2017," Giudice wrote.

The investigator also detailed an intercepted March 13 call between Mayfield and Gentry after an alleged drug courier got stopped by police near Friendship, Ark. Police recovered eight kilograms from her duffel bag, the DEA agent said.

GENTRY: "She called me. I was on the phone with her like 30 minutes, you know what I'm saying? While they (police who stopped her in Arkansas) were in the car with her, she wasn't speeding or nothing, man ............They (police) were asking her where she was going............she was real calm about it. Bridget been down (arrested/prison) four times, okay?"

MAYFIELD: "Right."

GENTRY: "So she's the OG (original gangster) in the gang. She straight. We don't have no worries when it comes to her......But she already know that if they take her in she fixing to do a bid (prison). She already know that. You see what I'm saying?"

MAYFIELD: "Right, right."

GENTRY: "Alright, I know, um, I know, I'm going to get another line and I'm going to call you from that other line. This is what I really need, bro, to be honest with you. I'm need you to come on to me, now, cause I gotta get that change (money that Mayfield owes Gentry). I got six more joints [kilogram of cocaine] now anyway. I don't know if you want to go back with them or not, but I got em."