Slot scanned the crime scene for any clues that might help him find the killer. He found drawers pulled open as if by a burglar, a gun safe that had been pried open, four spent shell casings and a 9-mm handgun with four bullets missing from its clip.
But Slot's investigation led him to one dead lead after another. Police tracking dogs picked up a scent in the house and followed it outside, but only to a dead end. Crime scene investigators found no fingerprints. They took the gun back to the crime lab for a closer examination, but a palm print they found wasn't big enough to identify one particular person.
"It seemed like every piece of evidence that we collected, we ran into dead ends," said crime scene investigator Max Hunter. "Left and right."
Bart Whitaker had good reason to believe he'd gotten away with murder, but Slot was beginning to doubt that the crime was the result of a burglary gone bad.
For one thing, he said, the dresser drawers were pulled out but not rifled through. There was no evidence of a break-in, and the only thing missing from the house was Bart Whitaker's cell phone.
"The burglar leaves the gun, leaves all the electronics, but takes a cell phone that we couldn't find in the scene," Slot said. "That was a real oddity that stuck out in everybody's mind."
As journalists descended on the story, one detail reported in a local paper raised a red flag for Slot: Bart Whitaker had not, in fact, graduated from Sam Houston State University. Actually, he had not even attended the school.
Soon after, a Sugar Land police officer recalled that he'd been called to the Whitaker house once before, two years earlier, regarding an allegation that Bart had threatened his parents' life.
"It was something that a friend overheard Bart talking to his roommate about, and they concluded that it was a misunderstanding that was based on the friend drinking and that there was nothing to it," Kent Whitaker said.
"All those little pieces set off bells and whistles in our heads -- just thinking, we need to start looking at the son," Slot said.
When they were released from the hospital, Bart moved back home to be with his father. For the next seven months, he spent every free moment with his father, studying the Bible, while the investigation made little progress.
He said he didn't come clean to his father, who had pledged to forgive the shooter, because he was "a coward."
"I didn't want to cause that pain on me primarily, and on anyone else, secondarily," he said. "So, I just was weak."
Then late one night, a man walked into the Sugar Land police station and introduced himself as a former friend of Bart Whitaker's. His name was Adam Hipp.
Hipp revealed that Bart had hatched a second, previously unknown murder plot that was aborted at the last minute -- a plot in which Hipp was recruited to be the shooter.
"One of the plans that he laid out to me that he and Bart had discussed was the exact mirror image of the actual crime," said Slot.
Once Hipp's story was verified, there was a new urgency to warn Kent Whitaker about his son. Slot encouraged Kent to move out of the home, but he refused.
"We feel wholeheartedly that he is responsible for this, and that you are living with a murderer," Slot recalled telling Kent Whitaker. "That you are living with a man who intended to murder you."