(CNN) -- From the beginning, the details of the shooting deaths of Uwe Rushing and his 13-year-old son, Stefan, in their Lawton, Oklahoma, home did not seem to add up, police said.
At first, Thorsten Gunter Rushing, 18, the son and brother of the victims, told police that two black men -- one of them armed -- forced their way into the home early on January 20 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.
"It didn't make a whole lot of sense," Capt. Craig Akard, a police spokesman, told CNN on Tuesday.
On Saturday, nearly a week after the slayings, Rushing and four friends -- described as polite young men and good students -- were arrested in connection with the double homicide, police said.
In addition to Rushing, the suspects, who await formal charges, were identified as Ethan Alexander Thompson, 19, Cody Xavier Davis, 19, Timothy Alan Delahoy, 18, and a 17-year-old, police said.
Akard said the young men "were involved in the murders in various ways to include planning, assisting beforehand, assisting during or assisting afterward." One of them was present at the time of the shooting, police said.
The slayings may have been planned for earlier. Two days before the January 20 shooting, police said, Uwe Rushing, 49, 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, where they had been watching TV. 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," Akard said. "The story of two guys coming in the house, doing the actions he said they did, running through the house, shooting, and then running back and shooting through another door. And the crime scene itself, where there was really nothing disturbed and it was hard for people to move through the house without knocking things over, much less running through the house."
Further investigation, including consultations with the medical examiner, began to unravel the version of events recounted by Rushing and the friend who was in the home at the time of the slayings, police said.
"The stories that we were getting weren't the same," Akard said. "The stories of what one said were not the same as what the others said, according to where they were supposed to be."
Investigators say they think Rushing used a handgun to shoot and kill his father and brother as the two watched TV.
"I doubt they knew what he was fixing to do," Akard said. "They knew he was in the house. They were watching TV. They probably weren't paying attention to what he was doing until it was too late."
The motive has not been confirmed, Akard said, but he added that there was "a little bit of turmoil" in the household. Aside from the report of the masked man showing up at the door days before the shooting, police had not received calls of domestic problems or abuse at the home.
"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."
Police recovered numerous guns in the home.
The five young men are being held on a probable cause affidavit as local prosecutors determine what charges will be filed, Akard said.