A 19-year-old man has killed his grandfather and tried to strangle his father at a home in Palm Coast, Florida.

Luke Ingram, who lives in Dunwoody, Georgia, was visiting his family in Florida when he beat up his 85-year-old grandfather, Darwin Larry Ingram, to death and then choked his father, Clint Ingram.

Clint told detectives that Luke, who has schizophrenia, had been acting strange while attending college in Georgia, so he convinced him to visit them. Luke arrived at their Florida residence Wednesday, WFLA News Channel 8 reported.

The father also said Luke was behaving strangely and was staring at Clint and Darwin during dinner. He later went to bed and locked his door because of his son's behavior, the father told the detectives.

Clint woke up later that night to "a growl-like sound and screaming." He followed the screams to find Darwin unresponsive and bleeding while Luke was sitting in a chair.

Luke attacked and choked Clint twice when the latter tried to call 911. The father managed to free himself and ran to a neighbor's house for help.

"My son attacked me. I need help," and then, "Call the ambulance, my dad is on the floor," Clint reportedly told the neighbor.

Flagler County Sheriff's Deputies responded at approximately 2:56 a.m. Wednesday after a 911 caller reported a man at their front door saying he was attacked.

Deputies entered the Ingrams' residence and "found the suspect standing near what appeared to be a severely injured or deceased male. He also was standing next to a blunt object that appeared to be used in the attack," Sheriff Rick Staly said, according to Flagler Live.

Luke initially complied with deputies but later showed resistance as they tried to arrest him.

Paramedics checked on the slain grandfather and pronounced him dead from significant blunt-force trauma at 3:24 a.m.

Luke tried to escape custody after being taken to the Flagler County Courthouse. He attacked law enforcement officers with what Staly described as "Herculean strength."

"I will kill you," he repeatedly said before being subdued and taken to the hospital, as per WFLA News Channel 8. He was later taken to a detention facility.

Clint was injured but did not suffer life-threatening injuries. A detective also sustained injuries and had to be taken to the hospital for medical attention.

"Fortunately, our detectives will recover from their injuries taking this violent offender off the streets and into the Green Roof Inn where he belongs," Staly said in a statement released by the sheriff's office. "The original crime scene reflected a very violent and brutal attack. We are working diligently to find answers as to what caused this tragic attack on family members early this morning. Our condolences to the family and all involved in this case."

Luke was charged with second-degree murder and domestic violence battery by strangulation among other changes.

Representational image: police car
Representational image (Source: Pixabay / tevenet)