HOUSTON -

The last of 24 people arrested as a result of the discovery of approximately 14,000 marijuana plants from 43 marijuana grow houses in Harris, Fort Bend and Montgomery counties have now been ordered to prison, according to the U.S. Attorney's Office, but two more suspects are still on the loose.

Yen Thi Do, 43, formerly of Boston, Mass., pleaded guilty to conspiring to maintain a premises for the manufacture, distribution, possession or use of marijuana. The other 23 defendants involved in the clandestine indoor marijuana grow organization pleaded guilty to the same charge. Do was sentenced to a total of 57 months in federal prison to be followed by a three-year-term of supervised release.

On Nov. 27, the USAO says the three highest ranking members of the organization charged in the case -- Thu Loan Dinh, 36, Van Long Tran, 34, and Thang Van Doan, 36 -- were sentenced. Each of the three defendants occupied leadership or managerial roles in the organization which generated hundreds of thousands of dollars each quarter with the sale of harvested high potency marijuana, according to U.S. attorneys. Dinh received a sentence of 108 months, while Tran and Doan will serve respective sentences of 97 and 78 months.

The remaining 20 defendants consisted of either marijuana grow house tenders who were paid to tend and harvest the marijuana plants in their respective grow house, or maintenance men who collected and removed garbage and/or did the lawn care. They received varying sentences up to 56 months in prison.

The investigation focused upon a domestic clandestine hydroponic marijuana cultivation and distribution organization in Harris, Montgomery and Fort Bend Counties. On Aug. 21, 2012, search warrants were executed at more than 60 residences identified during the course of the investigation -- 43 marijuana grow houses and 17 residences -- leading to the arrest of the 24 people and the seizure of approximately 14,000 marijuana plants, $121,000 in cash, numerous vehicles and hydroponic equipment.

Each of the grow houses had been leased from unsuspecting homeowners for use as a family residence. With one exception, none of the grow houses were actually occupied, but were used exclusively to grow marijuana. While the exterior and lawns of the leased houses were well maintained to avoid drawing the attention of the homeowners, neighbors or law enforcement, the interiors had been extensively modified to produce a rapid growth environment for the marijuana plants. The modified environment permitted the harvesting of 120–150 marijuana plants, or 12–15 pounds of high potency "bud" marijuana, every two months once a grow house had begun operation.

All of the defendants were born in Vietnam, most of whom were naturalized Canadian, Swedish or U.S. citizens, or permanent U.S. resident aliens. All foreign nationals are subject to deportation upon completing their prison terms.

Arrest warrants remain outstanding for two other suspected leaders/managers: Johnny Ng, 52, and Hein Le, 44. Anyone having information regarding their whereabouts is asked to contact DEA Houston at 713-693-3000 or their local DEA office.