Chad Bauman jail mugshot.

Chad Bauman, 35, of Lawrence, operated numerous businesses in and near his hometown in the years before his 2012 arrest: carpet cleaning, flooring, used cars, landscaping and a laundromat. But it was his decision to diversify into selling marijuana and cocaine that was the focus of Tuesday’s testimony in federal court.

One of 43 charged with conspiracy in 2012 as part of a $17 million federal drug conspiracy case, Bauman became the 15th codefendant to testify in the ongoing trial of Lawrence twins Los Rovell Dahda and Roosevelt Rico Dahda and their associate, Justin Pickel, of California.

Bauman and his wife, Carey Willming, had $1.4 million in property seized after their June 2012 arrests in the case — including a $13,000 engagement ring and a $600,000 property just outside of Lawrence that Bauman had been building since 2009. Willming has not yet testified and was sentenced to one year in prison in January.

Bauman, in federal custody and awaiting sentencing after pleading guilty to conspiracy in 2013, said Tuesday that he began selling marijuana in Lawrence around 2006 after he found a contact in Texas who supplied him with low-grade marijuana, or “brick weed.” Up to 140 pounds of marijuana would be shipped to a business he owned at 331 Maple St., Bauman said, while he either mailed or drove cash payments to Texas. Bauman said he also dealt cocaine throughout the conspiracy.

Bauman said he soon forged ties with codefendants Peter Park, of Olathe, and Wayne Swift, of California, and Los Dahda. He said Los Dahda’s involvement began at some point in 2007 after Bauman asked if he could help him sell off some of his low-grade marijuana.

Once Bauman’s relationship with his Texas source fell through and Park and Swift sought to pivot away from their Canadian suppliers, Bauman said the three trained their sights on northern California by fall 2008. It would become the source of much of the 1,000 kilograms of marijuana allegedly sold as part of the conspiracy. For awhile, Bauman said, the three split the cost of renting a warehouse to be used as part of Park and Swift’s California Connections business and as a front to ship larger quantities of marijuana and money back and forth in crates from California to Kansas.

On Tuesday, Bauman also took credit for the idea of using customized hidden fuel tanks to drive money or smaller amounts of marijuana between Kansas and California. He said an employee at his carpet business helped weld together custom tanks without knowing their true purpose. The first went in a pickup Bauman later sold to codefendant Stephen Rector. Swift used another, and Los Dahda had two trucks outfitted. Bauman said Tuesday that he estimated money and/or marijuana was driven up to 12 times using three different vehicles and that he, Swift, Park and Los Dahda would pool money for separate purchases of marijuana.

But by 2010, the ties between Bauman and several of the case’s players began to fray. Bauman said he moved out of the California Connections warehouse in Hayward, Calif., in fall 2010 after Park and Swift accused him of going behind their backs to help their mechanic purchase an auto business they sought to buy in Merriam.

Bauman said he soon rented a second California warehouse as a front under the guise of one of his businesses. He said Phillip Alarcon, another codefendant, and Los Dahda also had keys to the warehouse and Dahda would stay in living quarters at the warehouse occasionally. Bauman said his summer 2011 falling-out with Dahda occurred after Alarcon dried marijuana inside the warehouse, causing a noticeable odor. Bauman said he was upset with Dahda for not saying anything to Alarcon. But Bauman maintained contact with Alarcon, he said, because Alarcon was his cocaine supply and was holding on to some of Bauman’s cash.

Both Alarcon and Bauman have testified that Los Dahda didn’t want to be associated with cocaine.

Bauman will continue to testify when trial resumes Wednesday morning.