×

Livermore: Two sentenced to life for frenzied stabbing murder of 19-year-old woman

Livermore: Two sentenced to life for frenzied stabbing murder of 19-year-old woman

After five years, two Modesto residents have been given life sentences for the frenzied stabbing death of a 19-year-old co-worker who later identified them as she bled to death on a lonely Livermore road.

The defendants are now identified as 24-year-old Kate-Lynn Armstrong — who used to go by Daniel Gross — and Melissa Leonardo, 30, two Modesto residents who were engaged to be married at the time of the attack. The victim, 19-year-old Lizette Andrea Cuesta, of Tracy, was riding in a vehicle with both her killers when Armstrong allegedly stabbed her 43 times with a large knife.

Leonardo and Armstrong were engaged to be married at the time of the stabbing.

In an extremely rare move, Armstrong pleaded guilty to murder almost immediately after being charged. Leonardo also entered a no contest plea to second degree murder. Both were sentenced Sept. 19, at the East County Hall of Justice in Dublin, to 15 years to life, with Armstrong receiving one extra year for use of a knife during the murder.

Passing motorists discovered Cuesta mortally wounded but clinging to life around 2 a.m. on Feb. 12, 2018, on Tesla Road in unincorporated Livermore. Suffering from dozens of stab wounds and blood loss, she still managed to utter the names of her killers to the people who stopped to help her.

Related Articles

Crime and Public Safety |


Martinez police release body-worn camera footage of fatal Aug. 18 shooting

Crime and Public Safety |


Council members ask if Antioch police should call sheriff, CHP for help

Crime and Public Safety |


Gunshots in the grandstands: Why violence at high school football games is spiking and what can be done

Crime and Public Safety |


Authorities release name of man killed in police shooting at East Bay Toyota service center

Crime and Public Safety |


Oakland police arrest Colorado man in 2021 shootout that injured three

Cuesta, Armstrong, and Leonardo were all co-workers at a Carls Jr. and had planned to hang out that day, authorities said. Leonardo claimed that the stabbing took place after Armstrong and Cuesta engaged in consensual sexual activity in the backseat as she drove, adding that it didn’t bother her because “I’ve been cheated on before,” according to court records.

Armstrong and Leonardo were arrested just hours after the murder. Armstrong’s attorney, Deputy Public Defender Eric Mirzaian, blamed the stabbing on Armstrong’s mental illness that produces hallucinations and said Leonardo had triggered the whole thing by making a comment.

“Ms. Armstrong participated in the offense under duress not amounting to defense in that (Leonardo), who was pregnant with her child, made life-threatening threat to Ms. Armstrong that triggered command hallucination just prior to the criminal act,” Mirzaian wrote in an Aug. 11 letter to a probation officer.

Daniel Shriro, who represented Leonardo, said his client never actually participated in the stabbing.

“When Ms. Leonardo was given the opportunity to resolve the case by admitting to the crime she actually committed, aiding and abetting a second degree murder, she took responsibility and resolved the case,” Shriro said.