MEXICO CITY -- Eight members of a drug cartel were arrested in the torture and slaying of the brother of a former Mexican state attorney general, federal police announced Friday. The man had been forced to appear at gunpoint in a video saying his sister worked for a rival gang.

The body of Mario Gonzalez was found half buried in a house under construction in Chihuahua city after one of the suspects told officials where they could find him, federal police commissioner Facundo Rosas told a news conference. He said the body showed signs of torture.

The suspect said a man known as "The Vulture" ordered the group to kidnap Mario Angel Gonzalez Rodriguez, Rosas said. The men are suspected of working for the Sinaloa cartel.

Gonzalez, an attorney, was kidnapped from his office on Oct. 21 -- less than three weeks after his sister Patricia Gonzalez stepped down as Chihuahua state's attorney general due to a change of governor.

Days after the kidnapping, a video was posted on YouTube showing Gonzalez handcuffed and surrounded by five masked men pointing guns at him. Prodded by an interrogator, he blamed his sister for several notorious killings in the state and said both he and she had aided the "La Linea" drug gang.

Rosas said some of the men arrested had appeared in the video, which he said was shot as a safe house for the Sinaloa cartel.

Cartels have increasingly taken to releasing video clips of kidnapped police, officials and regular citizens admitting to crimes that aided rivals of the kidnappers. In several cases, the subject of the video has been found dead shortly afterward.

Federal police paraded the suspects -- some with bruised faces -- before television cameras on Friday. The announcement of the arrests came a day after the federal Attorney General's Office said it was opening and investigation into the case.

Gonzalez was attorney general during the most violent peacetime period in the history of Chihuahua state. A nearly three-year-old turf war between the Juarez and Sinaloa drug cartels has made Chihuahua the deadliest state in Mexico, and the border city of Ciudad Juarez one of the world's most dangerous cities.

In the video, the questioner prompted Mario Gonzalez into saying that his sister ordered several killings in Ciudad Juarez, where drug-gang violence has claimed more than 6,500 lives over the past three years. Among those, he said, was the 2008 killing of Armando Rodriguez, a crime reporter for the newspaper El Diario de Juarez.