District Attorney Matt Weintraub says 36-year-old Pavel Belous preyed on the victim who was eating in a McDonald's parking lot on Second Street Pike in Southampton the evening of March 11, 2021.
Weintraub says Belous threatened to murder him at knifepoint, claiming he's done it before.
Police say it was less than a week before that he allegedly killed a man in Philadelphia.
"Fortunately, this defendant picked the wrong person to victimize. This is one who fought back," said Weintraub.
Belous is behind bars, charged with kidnapping, and now attempted murder in Bucks County.
"At knifepoint, he abducted him and forced him to withdraw some money from an ATM. Then he took him to his home," said Weintraub.
There he threatened the victim, stating that he'd slit his throat, rape and kill his mother, and set fire to the house, officials said.
"The defendant saying, 'I killed someone before' was apparently not an idle boast. He's now charged with murder in Philadelphia," added Weintraub.
Weintraub says the same suspect was caught on camera along the 11000 block of Greiner Road in Philadelphia just six days earlier, on March 5.
The footage showed the alleged suspect leaving the house after fatally stabbing 62-year-old Jan Silverman and setting fire to his home.
In the Southhampton case, Belous was the one who was eventually stabbed in the back by the man he held up at knifepoint.
Upper Southhampton Township Police then arrested Belous, who hid in the victim's car, and tried to claim he was stabbed in a separate robbery.
"There comes a point in our lives when we have to decide to flee, be paralyzed, or fight for our lives. There was no choice to be made. This victim made the right choice," Weintraub said.