Perry Khaoone, 26, of Santa Rosa, was sentenced to eight years for kidnapping 24-year-old Terry Au and 10 years for an enhancement alleging the crime was gang-related. He pleaded guilty to the charges in May.
Judge Lawrence Antolini also sentenced Khaoone to eight months for possession of methamphetamine for sale.
Au's brother Vutha Au, who was to testify against the defendants at their trial, was later murdered. Five men are awaiting a trial for his murder.
Two other kidnapping defendants -- Boonlak Phanchanh and Pongsony Patrick Khaoone, Perry Khaoone's brother -- were sentenced last month. A fourth suspect, Dundo Xayyaphay, 21, of Santa Rosa, is still at large.
Prosecutors allege that all are Asian Boyz gang members. They were charged with abducting Au from his Santa Rosa home on Oct. 1, 2007. Deputy District Attorney Robert Waner said the three men entered Au's home while he was sleeping.
He said the men took Au to an undisclosed location in Sonoma County, held a box cutter to his throat, strangled him with a cord, burned him in the face with a cigarette and threatened to cut off his fingers and sell each one back to him.
At a preliminary hearing, Au testified he was kidnapped and beaten because he did not want to sell drugs for the Khaoones.
Boonlak Phanchanh, 23, of Santa Rosa, pleaded guilty to the charges in April. He was sentenced last month to three years for kidnapping Terry Au and to 10 years for the gang enhancement.
Pongsony Patrick Khaoone, 22, of Santa Rosa, pleaded guilty earlier this year to kidnapping and admitted the gang enhancement. He was sentenced to 15 years in prison in June.
The Sonoma County District Attorney's Office agreed to dismiss robbery, burglary and other charges against the Khaoones brothers and Phanchanh as part of the plea agreements.
Vutha Au was kidnapped and killed March 2, 2008. His body was found by a state parks ranger at in a parking lot at Blind Beach on the Sonoma Coast. He was shot nine times in the head, neck and torso.
Vutha Au was placed in the California Witness Relocation and Assistance Program but returned to the Santa Rosa area.
Five men, including Preston Phongsuvane Khaoone, 24, the Khaoones' brother, have been charged with Vutha Au's murder and with killing a witness to prevent his testimony. All are also alleged Asian Boyz gang members.
The other murder defendants are Tyrone Tay, 28, a Solano County resident; David Prak, 21, and his brother Sarith Prak, 24; and Quentin Russell, 27, all of Santa Rosa.