Several of the nine women and children who were brutally murdered by suspected gunman on an isolated highway in Mexico were reportedly shot at point-blank range in a targeted assassination.

The revelation comes as Mexican authorities reportedly refuse to allow American officials to investigate the massacre that left members of a small American Mormon village dead.

An American federal investigator disclosed to the New York Post that some of the evidence from the shootings could already be compromised.

'They were taken out of their cars and shot,' an American federal investigator said.

'It's kind of disturbing that the FBI has had no access to the crime scene, which is probably a disaster already because the Mexicans have allowed families to remove the bodies. Any evidence that could have been gathered is probably destroyed,' they added.

A Mexican investigator said the alleged hitmen, 'shot some of the victims at point-blank range'.

On Saturday the final funeral was held for victim Christina Marie Langford.

In the wake of the murders, some families are now fleeing their homes and returning across the border to America.

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Pictured: The three mothers and six young children who were savagely murdered by Mexican drug cartel gunman on November 4

Members of local Mormon communities and relatives of the extended Le Baron family attend the funeral held for Christina Marie Langford on Saturday

On Saturday the final funeral was held for victim Christina Marie Langford. Family members attend the funeral above

An 18-wheel caravan carrying around 100 members of the Mexican Mormon communities arrived in Arizona on Saturday.

Passengers packed their lives away and other personal items as they left behind the place their families had called home since the 1950s.

It's reported that Mexican authorities are still combing the scene in the state of Sonora for evidence, which is around 70 miles away from the Arizona border.

The Mexican government claims that the sudden attack on Monday, November 4, was the result of local drug cartel gunmen who mistook the Mormons' fleet of dark SUV's for a rival gang's.

Hector Mendoza, the Army chief of staff, said that the incident involved a faction of the Juarez cartel, La Linea, and their competitors from the Sinaloa Cartel - once controlled by Joaquin 'El Chapo' Guzman.

Mendoza says that the two groups had an altercation one day before the massacre in the same area.

He said that the gunmen allowed some of the surviving children to flee, signaling that 'it was not a targeted attack.'

However, both of the previous sources told the NY Post that this was simply a cover up done by the Mexican government to hide the attacks' true targets.

Young children and other loved ones stand beside Johnson's grave on Saturday

A funeral was held for Christina Maria Langford Johnson on Saturday, where family and loved ones mourned her passing

Pictured: The graves of Rhonita Maria Miller and her four children on Saturday

Christina Maria Langford Johnson, 29, was driving in a Chevy Suburban with her seven-month-old daughter, Faith, when the attack took place.

Johnson jumped out of her vehicle in an attempt to get the gunmen to stop, but she was fatally shot in the chest.

She placed baby Faith, who was in a car seat, on the Chevy's floor before exiting the car, saving the girl's life.

Another SUV was driven by Dawna Langford, 43, who was also traveling with Langford to a wedding in Chihuahua.

Gunmen killed Langford and two children, 11-year-old Trevor and two-year-old Rogan, while eight other children inside the vehicle were able to hide until it was safe.

Those surviving children, of which five were injured, hid in nearby brush before walking back to their community to get help.

The third mother was Rhonita Miller LeBaron, 30, who was driving a SUV with four of her seven children.

Miller's Tahoe reportedly suffered a flat tire while the family was on the way to pick her husband up from a Phoenix airport.

Before she could get help their car was caught in a hail of bullets, one of which struck the vehicles gas tank.

Miller and four of her children were incinerated in their SUV after the vehicle exploded into flames.

The children included Howard, 12, Krystal, 10, and 8-month-old twins Titus and Tiana.

Members of the LeBaron family look at the burned car on November 5 where some of the nine murdered members of the family were killed and burned during an ambush

All the victims were dual US-Mexican citizens and all are believed to have been members of the extended LeBaron family.

The LeBaron family settled in Sonora decades ago to practice polygamy after it was banned from the Mormon church in Utah.

The American investigator said: 'We've been saying all along that the Mexican government just doesn't want to investigate anything related to drug trafficking.'

'They will go to any extreme to cover everything up. It's completely corrupt, and it's only going to get worse.'

This source claims that government officials in Sonora state asked the FBI for help looking into the killings, but were cut off by Mexican federal officials.

An FBI spokesman told the NYP Saturday: 'The FBI continues to engage with our US government and Mexican law enforcement partners. We have offered assistance and stand ready to assist in the wake of this tragedy.'

Some members of the victim's families, who were part of Mormon communities in Sonora and Chihuahua, also expressed their doubts regarding the Mexican government's explanation.

Julian LeBaron told El Universal: 'They [the hitmen] had to know that these were women and children.'

He said some of the eight children who survived the attack said one mother left her truck with her hands up when she was fatally shot.

Adrian LaBaron, Johnson's father-in-law, revealed that their community has been without internet and cellphone service after the funeral service for Johnson ended.

He believes the Mexican government may have something to do with the downed communication lines.

He told DailyMail.com: 'As soon as we ended the burial our service stopped working. There were a lot of cameras broadcasting live. I don't know if anyone shut it off on purpose. I'm not sure, but I think so.'

'I believe that the [Mexican] Senate were the ones that ordered that all these lines of communication be cut off because they were active at funerals now and very strong things were spoken at the funeral.'

'They asked me a question, do you think that in Mexico they need the help of the United States with the organized crime situation? I told them no, that it definitely does not need the help of the United States, I told them that it needs the help of the entire world. That's how messed up Mexico is.'

Bryce Langford (pictured): '...to have to up and leave from one day to the next and leave all that behind, there's definitely a lot of sad people here'

Cole Langford, left, and Hayden Spenct, of the Mormon colony in La Mora, Mexico, hug during a rendezvous in a gas station in Douglas, Arizona

Members of the Mormon colony from La Mora, Mexico, greet each other during a rendezvous in a gas station in Douglas, Arizona on Saturday

On Saturday, families went in and out of a gas station in Douglas near the port of entry as the sun began to set as they prepared to move back to the U.S.

They filled up on gas, put air in their tires and got food before getting back on the road on their way to Tucson and Phoenix. Their trucks were loaded with boxes, bicycles, spare tires and bags, all their belongings packed as they left the communities in Mexico that their families have called home since the 1950s.

The families had lived in two hamlets in Mexico's Sonora state: La Mora and Colonia LeBaron. Other residents of the hamlets planned to depart in the coming days.

Monday's deadly attack occurred as the women traveled with their children to visit relatives.

Leah Langford-Staddon, a member of the Mormon community, said her family members spent the day packing before desperately preparing for the move.

Bryce Langford, whose mother is Dawna Langford, said the decision to leave was difficult.

'The assets that they've acquired down there are tremendous. And to have to up and leave from one day to the next and leave all that behind, there's definitely a lot of sad people here,' he said.

Adrian said that Langford's husband will be leaving for America with one of his other wives and their children.

He said: 'No way he is going to leave her alone. He has to go to work.'

Family members gather at the funeral for Miller and her four children on Friday

Relatives and members of the LeBaron community gathered together to attend Miller and her four children's funeral on Friday

Kenny Miller, Rhonita's father-in-law, spoke graveside Friday during her funeral and prayed for justice.

'We pray, Father, that good will come out of this terrible incident, that the way may be opened up for this country to find justice for those that don't have a voice,' he said.

Miller expressed the sentiment that the drug cartels have grown stronger since they began their stronghold in 2007.

More than 250,000 Mexicans have been killed in the continuing violence, several of which were related to drug-related crimes.

'I really believe that the cartels in Mexico have moved to another level of barbarity, they are as bad or worse than ISIS. ISIS have an ideology,' 65-year-old Rosa LeBaron said.

'These sicarios, why are they doing it? Out of greed and pure evil.'

She continued: 'This is so beyond comprehension, we're living like we're in Afghanistan, 100 miles from the U.S. border. They have to wipe these bad men out of Mexico just like the coalition that goes into Syria and these places.'

Johnson was buried Saturday in a plain pine casket and surrounded by members of the Mormon communities.

Her husband, Tyler Johnson, was seen holding a young boy during the funeral in LeBaron, Chihuahua, Mexico.

Men carry the remains of Dawna Langford and her two sons, Trevor and Rogan, before their burial at cemetery in La Mora on Thursday

Family members and friends look at the scorched remains of Rhonita Miller LeBaron's SUV Tahoe after it caught fire during the massacre (pictured)

While the attacks seem sudden, the LeBaron family and nearby cartels have been clashing for years.

The Mormon communities have long condemned the atrocities performed by Mexican cartels and resisted extortion attempts in the past.

In 2009, Julian LeBaron's older brother, Benjamin, was killed by traffickers after he led protest against the kidnapping of their 10-year-old brother Eric.

A cartel was holding Eric ransom for $1 million.

The family refused to pay the ransom and Eric was eventually released, but Benjamin and a neighbor, Luis Widmar, were killed by 20 armed men who invaded their home.

Julian said in a 2010 opinion piece in a Dallas newspapers: 'These are not isolated incidents.'

'Throughout our nation, countless people have lost their lives or their security in a similar manner, while politics of confusion and volumes of magic words appear to have more sway than reality.'