Joseph, 48, faces charges of first-degree murder and armed criminal action in connection with the May 30 deaths of his wife, Mary, and 18-year-old son, Matthew, at their home on West Cape Rock Drive.
Cape Girardeau County Circuit Judge Benjamin Lewis set the case for trial the week of Sept. 15, with jury selection to begin Sept. 11 in Cole County, Mo.
In court Tuesday, Lewis declined to elaborate on his Oct. 29 decision to deny a defense motion to suppress a videotape of an interview with police officers in which Joseph made several incriminating statements.
Joseph's attorney, Bryan Greaser, noted Lewis' ruling on the motion did not include his grounds for rejecting it.
"The motion to suppress is overruled," Lewis told Greaser. "I'm not required to write an opinion on it."
At an Oct. 18 motion hearing, Cape Girardeau Police Department detectives acknowledged Joseph had asked for his attorney several times during their June 4 conversation with him in the intensive care unit at Barnes-Jewish Hospital in St. Louis, where he was being treated for a gunshot wound to the head.
In their testimony, the detectives characterized the conversation as an interview rather than an interrogation and said their questions to Joseph were "not guilt-seeking."
Outside the courtroom Tuesday, Lewis said he agreed with prosecutors' arguments in favor of including the videotape as evidence.
He declined to elaborate further, but briefs filed in the case reveal both sides' arguments.
Greaser argued that by continuing to ask Joseph questions after he told them he wanted his attorney present, the detectives violated his constitutional rights.
In his motion, Greaser said Joseph's statements "were not voluntary and was the result of mental coercion" as the two detectives stood at his bedside and asked questions in "'tag-team' fashion."
Defendants have the right to remain silent and to have an attorney present when they are interrogated while in police custody, assistant prosecuting attorney Angel Woodruff acknowledged in her response to the motion, but those rights apply only if the defendant is in custody.
While Joseph's physical condition would have made it unwise for him to attempt to leave the room, he was not in custody and could have stopped answering the detectives' questions or asked them to leave at any point, Woodruff wrote.
Joseph was not under arrest before, during or immediately after the officers' visit, so they were under no legal obligation to advise him of his rights or to stop questioning him, Woodruff wrote.
"While it is true that Defendant did indicate he wished to speak to his attorney, he never asked the officers to leave," Woodruff wrote. "In fact, Defendant indicated he was fine when repeatedly asked by the officers and by medical personnel if he was doing OK. Defendant was also specifically asked by one of his nurses if it was OK for the officers to stay, and Defendant responded that it was."
Woodruff dismissed Greaser's argument that Joseph was coerced into incriminating himself, noting he was alert, said he was not in pain and knew where he was and why he was there.
"The defendant's independent will was plainly evidence in his refusal to provide the officers with any details surrounding the murders of his wife and son. ... In short, the defendant was calling the shots during his encounter with police," Woodruff wrote.
Greaser had requested a change of venue in August, citing pretrial publicity.
Rather than move the trial out of the area, Lewis approved a defense request to import a jury from Cole County.
The case has been the focus of extensive media coverage, partly because of questions about Joseph's financial dealings.
At a preliminary hearing in July, Joseph's brother-in-law testified Joseph was the target of a federal investigation and that he had been worried about financial problems, including the loss of money he had invested for other people.
In April, Joseph's name came up in connection with a Scott County financial exploitation case in which a Cape Girardeau man is accused of taking $220,000 from an elderly couple, telling them he would invest the money in annuities.
Instead, most of the money went to Joseph, a Scott County detective has said.
Although Joseph has not been charged in connection with that case, he told Detective Sgt. Branden Caid he was running a 60-member "investment club," Caid said in June.
Several club members have asked media outlets, law enforcement agencies and local attorneys for help recovering the money they invested with Joseph.
1220 W. Cape Rock Drive, Cape Girardeau, Mo.