Though nearly seven years have passed since nine Mormon women and children were massacred by a cartel’s army of assassins, no one has been convicted of the killings — a grim illustration of the failures of Mexico’s justice system, the devastated father and grandfather of several of the victims told The Post.

The three women and six children were killed Nov. 4, 2019, when gunmen ambushed their SUVs on a road near Bavispe, Sonora, about 70 miles south of the US-Mexico border.

Rhonita Miller and Christina Langford were traveling with their children to a wedding in Colonia LeBarón, while Dawna Ray Langford and her kids were on their way to meet her husband in Arizona when members of La Línea — the armed wing of the Juárez Cartel — opened fire on the group’s three vehicles. They then set fire to the truck carrying Miller and her four children.

Dawna Ray Langford, two of her children, and Christina Langford were also killed in the ambush, which seven of Dawn’s children and Christina’s 7-month-old baby survived.

About 100 people participated in the horrific attack — which authorities said was carried out because the gunmen wrongly believed the convoy belonged to rival gang Los Salazar.

But Miller’s father, Adrián LeBarón, told The Post he has a hard time believing that Mexico’s court system will land many convictions for the killings, if any at all.

“I’m not frustrated, because – as the saying goes – expectations breed frustration,” LeBarón said.

“I still don’t understand why that tragedy had to happen. Damn it, what the hell was going on in Mexico for things like that to happen?” LeBarón said. “For me, it’s a wake-up call to those realities, and the fact that these things keep happening tells me we’re screwed. There are people accused, but no one has been sentenced (on murder charges).”

Prosecutors have landed only two convictions in connection to the carnage — but none for the killings themselves. One gang member was sentenced to 12 years for organized crime and weapons possession, and a former public security chief got 15 years for organized crime.

Jacinto “El Monster” Galindo, a former police officer and soldier, is the only person to be indicted for murder.

“I don’t have confidence in our justice system; I have more faith in the US system,” LeBarón said.

The grieving family traveled to Washington, D.C., one month after a massacre and appealed to President Trump to designate Mexican cartels as terror organizations.

Less than a month into Trump’s second term, six Mexican cartels were designated as Foreign Terrorist Organizations (FTO).

The Juárez Cartel was not on the initial list but was added in July, which meant that the US could go after La Línea and extradite members to the US to be tried for crimes they have committed.

La Línea was formed by retired and active-duty local and state cops in 2008 as the Juárez Cartel’s chief enforcement unit in Ciudad Juárez, a city that has since been ravaged by their battles with rival cartels. 

But Mexican authorities recently made moves against the deadly group.

La Línea regional leader Epifanio Villa and his son, Alejandro Villa, were arrested by the military Tuesday in Manuel Ojinaga, Chihuahua, less than four miles from Presidio, Texas, for charges unrelated to the 2019 killings.

Villa allegedly is in charge overseeing the production and trafficking of drugs for the street gang in the border city. He is also accused of leading the gang’s migrant trafficking operation from Mexico to the United States.

LeBarón believes Villa’s arrest was possible because of all that Trump and Secretary of State Marco Rubio had done in designating the Juárez Cartel a terrorist organization.

“When the United States takes the step of designating them as FTOs – now we’re talking,” LeBarón said.