Lori Vallow Daybell's Brother Alex Cox's Cause of Death Determined by Medical Examiner

The Maricopa County medical examiner's office released its report Friday showing that Alex, 51, died from a blood clot in an artery in his lungs.

An Arizona medical examiner has ruled that Lori Vallow Daybell's brother, Alex Cox, died of natural causes when he was found unresponsive at home on Dec. 12. The Maricopa County medical examiner's office released its report Friday showing that Alex, 51, died from a blood clot in an artery in his lungs months after he shot and killed Lori's fourth husband, Charles Vallow.

Alex claimed he fired in self-defense and was not charged in the July 11 shooting.

Alex's official cause of death is listed as bilateral pulmonary thromboemboli, and the contributing cause of death is listed as atheroschlerotic and hypertensive cardiovascular disease, which is caused by high blood pressure, according to the report, which was shared online by EastIdahoNews.com.

Alex died just two weeks after marrying his wife, Zulema Pastenes, in Las Vegas. In a statement made through their attorneys, Zulema and Alex's other family members expressed their "comfort" in the findings. 

"Alex’s widow, Zulema Pastenes, along with his mother, Janis Cox, sister, Summer Shiflet, and his niece, Melani Pawlowski are pleased to see the report confirms what they knew and maintained since Alex’s death on December 12, 2019," attorneys Robert P. Jarvis and Garrett L. Smith wrote in the statement.

"In interviews with many news agencies, the family stated numerous times what they knew to be true—Alex’s death had no sinister aspect. With a degree of vindication, the family hopes that the confirmation of this truth will help all to step back, take a breath, and allow the truth to unfold through the process," they added. "Rampant rumors of evil plots and conspiracy robbed the family of their time to grieve the loss of their husband, son, brother, and uncle. Even so, the family finds comfort in the medical examiner’s finding that Alex Cox died of natural causes."

The medical examiner's ruling does not mean the investigation into Alex's death is over, however. 

“The next step for the Gilbert Police Department detectives assigned to the case will be to review the autopsy report in its entirety,” Gilbert Police spokeswoman Dani Covey told EastIdahoNews.com. “This case is still active at this time.”

Alex's death is one of three deaths surrounding Lori and her fifth husband, Chad Daybell, that investigators have been looking into. Chad and Lori are currently under investigation by the Idaho Attorney General's office for "conspiracy, attempted murder and/or murder" in the death of Chad's first wife, Tammy.

Tammy Daybell, 49, was found dead at her home Oct. 19 and Chad and Lori married weeks later. Neither Chad nor Lori has been charged with a crime in Tammy's death and both have denied all allegations of wrongdoing.

The investigations into the deaths of Alex, Tammy and Charles are all part of the ongoing search for Lori's missing children, Joshua "JJ" Vallow, 7, and Tylee Ryan, 17. The siblings have been missing for more than seven months. 

Alex was present on several dates that are of interest to investigators, including the shooting of Charles on July 11. Alex, Lori, JJ and Tylee then all took a trip to Yellowstone National Park together on Sept. 8, according to the FBI, and that trip was the last time anyone saw Tylee.

The FBI has asked anyone who was at the park on Sept. 8 to submit "photos and video that may assist in the investigation" into the siblings' disappearance. Agents also shared a photo of Alex's silver 2017 Ford F-150 pickup truck and its license plate, CPQUINT. The FBI has set up a special tips page for the case here

The ex-husband of Lori's niece, Brandon Boudreaux, also claims that Alex is the man who shot at him outside of his home in Arizona on Oct. 2. Brandon and Lori's niece, Melani Pawlowski, are involved in a custody battle over their four children. Brandon hired private investigator Rich Robertson after the alleged shooting. 

In a 911 call from the incident, Brandon can be heard telling the dispatcher, "someone just shot my window." Robertson said he and Brandon met on Oct. 13. 

"He was so anxious that we actually met in my office on a Sunday morning and he told me this wild tale of killing and missing people and religious cults and that he had been the victim of a drive-by shooting," Robertson told InsideEdition.com. "He was the target of the drive-by shooting and he thought that he recognized his assailant as being Alex Cox." 

Alex was not charged in the incident, which is under investigation. 

Robertson said he observed Alex helping Melani pack up her own home in Arizona to move to Rexburg on Oct. 31. Both Alex and Melani joined Lori there. 

Alex is also mentioned in a document described by attorneys Jarvis and Smith as a "summary of information" Melani's new husband, Ian Pawlowski, gave to law enforcement after meeting with them.

In the document, Ian wrote that Melani told him she was concerned that Alex might have had something to do with the disappearance of JJ and Tylee. 

"Melani had been told by Chad and Lori that their children had been possessed and had become zombies," Pawlowski wrote. "She shared concerns that she's been told Brandon [Boudreaux] needed to die and that may indicate that Tylee and JJ needed to die as well. Chad and Lori both deny all allegations of wrongdoing. 

"She told me she was worried that Al [Alex Cox] may have had to 'take care' of the kids. She explained that Al had great faith and never wavered in his trust in the Lord. No task would be too difficult or great for him. When I asked for clarification, she restated her concern verbatim."

Melani's attorneys, Jarvis and Smith, issued a statement on March 25 accusing Brandon of "lies and deception" and said "Ian’s summary of information given to law enforcement, written and delivered to Melani’s lawyers, includes his conclusions that Melani is not a part of the extremist group." 

In a new interview with EastIdahoNews.com, Melani said "still to this day, I don’t know what happened in the shooting" Brandon described.

"I’ve been trying to put the pieces together of what’s going on because I don’t have the facts, but the knowledge that I do have – it doesn’t add up to all the speculation and rumors that are flying around," Melani told EastIdahoNews.com. "To this day, I have not seen one shred of evidence about this shooting Brandon’s claiming that leads me to believe that it was Alex Cox." 

Alex and Melani both married last fall. Marriage certificates show Alex married Zulema on Nov. 29, and then the couple served as witnesses for the Las Vegas wedding of Melani and Ian the next day. 

Alex was found unresponsive at home two weeks later on Dec. 12. A transcript of the 911 call obtained by KTVB shows that the person calling police said Alex was his mother's boyfriend and that he was not breathing. Alex later died. 

Lori is currently being held on $1 million bond in an Idaho jail and has been charged with two counts of felony desertion of a child in the disappearance of JJ and Tylee, as well as misdemeanor charges of resisting and obstructing an officer, solicitation of a crime and contempt. Her preliminary hearing has been set for July 9 and 10. 

Lori has pleaded not guilty and denies all allegations of wrongdoing. Her attorney, Mark Means, did not respond to InsideEdition.com's request for comment.

The Rexburg Police Department asks anyone with information regarding the children's whereabouts or welfare to contact the department at 1-208-359-3000 or the National Center for Missing and Exploited Children (NCMEC) at 1-800-THE-LOST.  

JJ has brown hair and brown eyes, is 4 feet tall and weighs 50 pounds. He has autism and "may be in need of medical attention," according to authorities. Tylee has blonde hair and blue eyes, is 5 feet tall and weighs 160 pounds.