On the evening of February 24, 1985, Westchester County police officer Gary Stymiloski notified headquarters that he was making a routine traffic stop in Yonkers, New York. Moments later, after spotting shotgun shells in the car, Stymiloski radioed for support. Reinforcements arrived in time to find him dying, in his cruiser, with a single bullet in his brain.

The suspect vehicle was found abandoned in the Bronx and traced to Alex Mengel, age 30, an immigrant from Guyana who entered the United States in November 1976. A tool and die maker by trade, Mengel had logged one arrest - for assaulting his ex-wife - in 1984. Investigators learned that Mengel was returning from a weekend's shooting in the Catskills, traveling with friends, when Stymiloski flagged him down for speeding. Two of his companions, held in custody as material witnesses, agreed that the shooting was senseless and unprovoked, leading to issuance of a murder warrant on February 27.

Three days later, in Toronto, local officers spotted Mengel outside a shopping mall. The fugitive crashed his car into a wall while trying to escape, then swerved into a dead-end street where he was cornered and arrested. The stolen vehicle was registered to Beverly Capone, an IBM computer programmer reported missing by her family, in Mount Vernon, New York, on February 26. Two pistols and a woman's scalp were found inside the car; ballistics tests established that one of the guns had been used to kill Officer Stymiloski in Yonkers.

On March 4, while Mengel fought extradition from Canada, New York state police found items belonging to Beverly Capone in a Catskills summer cabin near Durham. Eleven days later, the woman's remains were discovered in heavy woods a half-mile from the cabin; she had been stabbed once in the chest, her scalp and the skin of her face sliced away by her killer. Tissue samples from the body made a positive match with the scalp recovered from Capone's car in Toronto.

With the new evidence in hand, authorities linked Mengel with the attempted abduction of a 13-year-old girl in Skaneateles, New York, southwest of Syracuse, on February 27. The child was delivering papers when a stranger, wearing lipstick and an ill-fitting wig, tried to snatch her off the street. Escaping without injury, she agreed with detectives that the "wig" might just as well have been a woman's scalp.

On March 26, Canadian authorities ordered Mengel's deportation to New York as an illegal alien with insufficient money to support himself. Two days later, a grand jury in Westchester County indicted Mengel for first-degree murder in the slaying of Officer Stymiloski. Greene County followed suit on April 8, charging the prisoner with second-degree murder in the case of Beverly Capone.

On April 26, returning under guard from his arraignment in Greene County, Mengel tried to escape from his state police escort on the Taconic State Parkway. Undaunted by handcuffs and chains, he grappled with one guard, seizing the officer's sidearm, and was killed by the driver before he could squeeze off a shot.