(CNN) -- An Oklahoma teenager and four of his friends have been formally charged in connection with the slayings of the teen's father and younger brother, authorities said Friday.
Police said Thorsten Gunter Rushing, 18, allegedly shot his father, Uwe Rushing, 49, and his 13-year-old brother, Stefan, on January 20 before calling police to report a home invasion in an elaborate ruse involving four of his friends.
After allegedly shooting his dad and brother as they watched television, Rushing smothered his brother to death because he was not "bleeding out fast enough," according to an affidavit filed in an Oklahoma state court.
From the beginning, police said, the details of the shootings in Lawton did not add up. Initially, Rushing told police that two black men -- one of them armed -- forced their way into the home before Rushing chased them away with a shotgun, police said.
Later, the intruders were described as white and Hispanic. Though the gunman was described as running through the house while firing his weapon, police said, not a single item in the home appeared to be knocked over.
On Thursday, Rushing and Ethan Alexander Thompson, 19, were formally charged with two counts of first-degree murder and conspiracy to commit murder, according to court papers.
Timothy Alan Delahoy Jr., 18, was charged with two counts of conspiracy to commit murder and two counts of accessory after the fact of murder. Cody Xavier Davis, 19, was charged with two counts of conspiracy to commit murder and two counts of accessory after the fact of murder.
On Friday, Wesley Bankston, 17, was charged with two counts of first-degree murder and two counts of conspiracy to commit murder, police said. He was charged as an adult, but his lawyer told the court that she would seek to have him tried as a juvenile.
All five have pleaded not guilty.
The teens were being held on bond of between $2 million and $5 million, court officials said. Lawyers for Rushing and Bankston declined to comment; attorneys for the others could not immediately be reached for comment.
A court affidavit obtained by CNN said that on January 20 Thorsten Rushing allegedly met with Thompson and Bankston and they agreed that Thompson would help remove the evidence after the shootings and that Bankston would drive.
At the Rushing home, the affidavit said, Thompson hid in a closet for several hours before Thorsten Rushing allegedly killed his father and brother. He used a 9mm Glock to shoot them, authorities contend.
Police said Thorsten Rushing and Thompson then allegedly pumped two shots into a wall to make it seem as if the intruders shot at Thorsten. The affidavit said the teens collected the evidence in a bag and called Bankston so that he could drive them to dispose of it. Later, Thorsten Rushing allegedly fired a shotgun blast into a wall before calling 911.
After the slayings, the five teens met at the home of Thorsten Rushing's grandparents to discuss what happened, the affidavit said.
They allegedly talked about burning the evidence bag but keeping the Glock in a car belonging to Bankston's father. Delahoy, Davis and Bankston later took outdoor target practice with the "murder weapon," the affidavit said.
Last Saturday, nearly a week after the slayings, Rushing and his four friends -- described as polite young men and good students -- were arrested after investigators discovered holes in their stories, police said.
The slayings were supposed to happen earlier. Two days before the January 20 shooting, police said, Uwe Rushing bumped into a masked man as he was leaving the house. The masked man ran off.
A couple of days later, police responded to a 2:05 a.m. call of a shooting at the Rushing home. The bodies of the father and son were found in the living room. Thorsten Rushing told investigators that two men entered the home through a rear door, and one of them shot his father and brother before Rushing got a shotgun and fired at the men, who fled.
"The story and the evidence and the crime scene just didn't add up to where it was making any sense," said Capt. Craig Akard, Lawton police spokesman.
Further investigation, including consultations with the medical examiner, began to unravel the version of events recounted by Rushing and his friends, police said.
The motive has not been confirmed, Akard said, but he added that there was "a little bit of turmoil" in the household.
"Most of the people we talked to said the family was, I guess you could say, the Three Musketeers," Akard said. "They got along. They did stuff together. But now that this happened, we're starting to hear, 'OK, maybe it wasn't quite as good as people said it was.' Apparently, it wasn't all as nice as what we heard."