Horror moment Pennsylvania mom tries to shoot her ex-husband’s teenage nephew minutes after murdering her two sons, 13 and 9, as they slept in sick revenge plot: Killer left chilling note saying ‘Call 911! My children are dead in bed’

This is the horrific moment a 40-year-old Pennsylvania mother tried to shoot her ex-husband's teenage nephew, moments after shooting her two school-age sons as they slept in their bed.

Trinh Nguyen will now spend the rest of her life in prison after pleading guilty to two counts of first-degree murder in the May 2022 killings of both of her sons, nine-year-old Nelson and 13-year-old Jeffrey.

Police revealed how she planned their murders for over a week before carrying out the shocking massacre in a sick revenge plot against her former husband.

Earlier this week, Judge Raymond F. McHugh sentenced Nguyen to two life sentences without the possibility of parole for killing the boys and attempting to kill the teen.

Minutes after the boys were shot in their beds, Nguyen could be seen outside the home where she tried to shoot the teen.

Security footage shows the pair struggling as 19-year-old Gianni Melchiondo tried to free the gun from Nguyen, who fired twice.

The video shows Nguyen trying to shoot, but the gun never fired and Melchiondo was able to disarm her.

Incredibly, two of the gun's chambers were empty when she tried to shoot the teenager, meaning he was saved from almost certain death.

Melchiondo's mother, the aunt of the young boys Jeffrey and Nelson, testified in court, “I thank the Lord all this time that the gun misfired.”

The negotiated plea and sentence “ensures that the defendant will die within the four walls of a correctional facility” because of her unfathomable actions, First Assistant District Attorney Jen Schorn said after the hearing.

'I mean, thank goodness for the cousin that the gun was defective or she didn't fire it right or whatever, and there's a video out there where she was captured trying to shoot him,” Schorn shared Law & Crime during an interview on Friday

'The [jamming of the gun] had the cousin intervene and disarm her, and then she continued to try to convince him that the gun was not loaded.

“We know for a fact that if Gianni had not acted, he would have suffered a fatal gunshot wound and you only know who else she would have killed before attempting to commit suicide.”

After the shootings on the morning of May 2, 2022, Upper Makefield Township police rushed to the home after reports of an armed person.

Police officers checked Nguyen's home and found the boys seriously injured in their bed with gunshot wounds to their heads.

Both boys were taken to hospital but ultimately died four days later.

Nguyen's sons had been on life support before being pronounced dead at Children's Hospital of Philadelphia.

The pair were kept alive despite doctors' bleak prognosis so their organs could be donated to people in need.

Hours after the shooting, police found Nguyen in her minivan parked at a nearby church. She was immediately taken into custody.

Detectives found .38-caliber ammunition along with packets of heroin, some of which she had consumed in an attempt to commit suicide.

There was a note on the dashboard that read, “Please call 911! My children are dead in their beds at 119 Timber Ridge Rd 18940'

Detectives searched the home and discovered a handwritten will dated a week before the shooting.

There was also a .38-caliber revolver in front of the house.

Speaking with Law & crime Prosecutor Schorn said the woman convinced herself she had to kill the young boys.

“She objected to her one son, saying she was afraid he would look like his father, which was completely pointless and ridiculous, while she said her other son was too naive and good for this world, so she wanted his son take. life to spare him,” Schorn explained.

“She was facing deportation and made it seem like she was struggling with poverty even though she was quite comfortable financially after the divorce, but she…wanted to create us this false story to justify the most terrible crime and honestly one of the worst I have ever seen.”

Bucks County and Upper Makefield detectives discovered that Nguyen had planned the murders and left a handwritten will instructing the recipient on what to do with both her and her son's remains.

DA Schorn said Nguyen blamed others for the problems in her life, including the impending eviction from the Timber Ridge home where she lived after a rent dispute with her ex-husband.

“Clearly our evidence shows that this defendant was so evil in nature that she made these plans,” Schorn said.

“She wrote a manifesto outlining what she was going to do, and you could see that in the hatred she had for others and the people she blamed.”

The letter also told the recipient what to do with her own remains, confirming the police's earlier suspicions that the mother intended to commit suicide once the deed was done.

Family and friends who attended the court earlier this week made emotional impact statements detailing how their lives have been affected by the deaths of the two young boys, described as caring and cheerful, and loved by all who knew them.

The boys were shown in court in a specially prepared slide show showing them smiling together.

DA Schorn said the entire family had felt immense sadness after the murders.

“You just saw the ripple effect of the sadness. Layer after layer after layer, by family members of the community, it's just heartbreaking.

“They showed so much strength and dignity when they came to court and made impact statements,” Schorn said.

“We can't ease the pain, but at least we were able to get justice for Nelson and Jeffrey and their cousin who survived the disaster. [murder] attempt.'