SUMTER COUNTY, Fla. -- Investigators said Shawn Fortner, 27, forced his way into the Wildwood home of Terry and Colleen France as they were grilling steaks for dinner.
Terry France said Fortner threatened to kill them both and their son.
"He pointed at my wife and he says 'You're next. You're going to die,'" Terry France said.
Terry France said Fortner fought with him and tried to grab a steak knife.
He said Colleen rushed to the hit the family's security alarm. She hit all the buttons: panic, police, fire and medical.
Fortner heard the panic alarm and ran from the house. Officers responding to the break-in spotted his car and started a chase.
"He was driving erratic. He was driving high rates of speed. He clearly did not want to pull over," said.
Finally cornered in Wildwood, officers made the arrest.
The officers and deputies knew they'd arrested a home invasion suspect, but they didn't know the guy in the back of the patrol car was also a suspect in a killing.
Orange County investigators said Fortner killed his grandmother at her home in Ocoee before running to Sumter County and the France family, who are distant relatives.
"They were in danger. He had nothing to lose because he'd already committed a homicide," Sumter County Sheriff Bill Farmer said.
Fortner was transported back to Orange County to face murder charges in the death of his grandmother.
He's being held there without bond.
Video: WFTV Orlando