The 34-year-old woman was waiting in her silver Mercedes at the store shortly before 3 a.m., Boynton Beach Police spokeswoman Stephanie Slater said. She was meeting her ex to pick up her 4-year-old son for whom they share custody.

Roosevelt Mondesir, 52, arrived in his white Jaguar without the boy and began throwing gasoline on the unidentified woman's car and body, according to a police affidavit. She tried to run away, but police said the man chased her with a knife and then ignited her.

In graphic surveillance video, a man can be seen threatening a woman with a large knife, struggling in the doorway of the store. "Get away from me!" she can be heard shouting.

They disappear from view until she returns in a massive fireball, screaming and running around the parking lot.