Twenty-four-year-old Jubal Alexander had been living in his pickup truck, parked under a farm-to-market road in southeast Texas, according to local news reports.
He was saving money to pay bills while working nights as a pipe-fitter at an area chemical plant, family and friends told ABC News. And, they said, he was never in any trouble.
Alexander was discovered dead earlier this month, police said.
When they stumbled upon the grisly scene, they found Alexander slain in the front seat of his truck. His head had been removed - and was nowhere to be found.
"They cut my son's head off and they took my son's head. Who would do that?" his father, who was not named, told ABC affiliate KTRK. "They won't even let me see him."
The Brazoria County Sheriff's Office is investigating after deputies were called May 3 about a headless body in a blue Chevrolet pickup parked at the Austin Bayou Boat Ramp on FM 2004 in Brazoria County, not far from Houston.
Deputies told CBS affiliate KHOU that a fisherman said he had been on the water all day and realised the truck had not moved.
Captain Chris Kincheloe of the Brazoria County Sheriff's Department told the Port Arthur News that authorities searched the grounds using cadaver dogs and the waters in boats but could not find Alexander's head.
"We have absolutely no idea of the motive, but the mere fact that we have an unexplained homicide causes concern," he told the newspaper.
Authorities said the victim was later identified through fingerprint analysis as Jubal Dee Alexander from Port Arthur, Texas. Alexander had been seen just a few days earlier, when he had dinner with his father in nearby Angleton, according to KTRK.
"He wanted me to be proud of him, so he worked exceptionally hard," the father told the news station. "His shift was a 10-hour, maybe a 13-hour shift. He worked all night long."
Alexander's family told KTRK that it did not appear that he had been robbed because his wallet - filled with cash - was still inside the truck, along with Alexander's guitar.
"I want people to know," he told the news station. "I don't want this to be swept under the rug or die in a cold case."