One week after an alleged robber was shot dead at a marijuana-laden Upper Lake property, details about the shooting remain foggy.

"We're not sure who pulled the trigger," Lake County District Attorney Don Anderson said Tuesday.

Lake County sheriff's detectives are still investigating whether James Michael Jean, 50, or his wife, Nora Katherine Jean, 49, shot Maurice Watts, 30, a Lake County resident with a history of drug-related arrests.

Neither one has been charged with the shooting. Investigators are still trying to determine who fired the fatal shot and whether the shooting was justified, law enforcement sources said.

James Jean is a convicted felon who is prohibited from possessing firearms.

While the shooting itself remains under investigation, the District Attorney's Office is moving forward with a case focusing on the drugs and weapons found when deputies served search warrants on three locations connected with the Jeans.

Law enforcement officers seized nearly 1,000 pounds of marijuana and 17 firearms at the three locations. The weapons included several assault rifles and illegal ammunition, according to the Sheriff's Office.

The Jeans on Tuesday remained in the Lake County jail on $500,000 bail each. They are charged with multiple felonies.

On Monday, they were arraigned in Lake County Superior Court on charges that include possession of marijuana for sale in connection with the two Nice locations. One is a house. The other is a shop that installs stereos and alarm systems in vehicles.

No charges have been filed regarding the marijuana found hidden in a building near the Jeans' residence, which is located on a hilltop about five miles north of Upper Lake and near the edge of the Mendocino National Forest.

The couple also is charged with being armed with multiple firearms while committing the alleged drug offenses, according to the complaint filed by the Lake County District Attorney's Office.

James Jean additionally is charged with being a felon illegally in possession of weapons and ammunition. He has a prior criminal record that includes convictions in April 1992 for multiple counts of second-degree robbery in Southern California. He served almost five years in state prison and three more on parole, according to the Department of Corrections. Details of his crimes were unavailable Tuesday.

James Jean told detectives that Watts was trying to break into his residence just before 10 a.m. Christmas when he was shot.

Watts' body was found near a structure and in an area of the property where marijuana previously had been growing, according to the Sheriff's Office. They did not divulge how close it was to the Jeans' home.

Officials said they found a fake gun near Watts' body.

Lake County Sheriff Frank Rivero said it appears that Watts was attempting to rob the Jeans of marijuana.

Officials said Watts had been shot but did not reveal whether it was more than once. An autopsy was conducted Monday but the results are not yet available, officials said.