A former prosecutor said Tuesday that the Grand Teton County coroner's ruling that Gabby Petito's homicide was caused by strangulation will likely result in a first-degree murder charge for whoever is arrested in the 22-year-old's death. 

"It almost always gets you first-degree murder because premeditation can be formed in an instant," Mark Eiglarsh, a criminal defense attorney and former Miami-Dade County prosecutor, told Fox News on Tuesday. 

"You put your hands around the neck, that’s an unwanted touching, that’s simple battery or assault. Then you start to squeeze, your argument could be, ‘Well, I just wanted to scare them.' But then you contuse to affix pressure… There’s a certain amount of minimal time that someone needs to do that before somebody is dead," Eiglarsh said. 

"I think there’s a strong argument that if premeditation didn’t exist prior to the physical contact, it certainly was developed at some point during the strangulation."

BRIAN LAUNDRIE'S LAWYER CALLS GABBY PETITO'S DEATH A 'TRAGEDY' AFTER CORONER SAYS SHE WAS STRANGLED

Aside from the manner and cause of death, the Teton County coroner could not release much more information about the autopsy due to Wyoming state law. 

Gabby Petito and Brian Laundrie were involved in a domestic incident in Moab, Utah on Aug. 12. 

Gabby Petito and Brian Laundrie were involved in a domestic incident in Moab, Utah on Aug. 12.  (Moab City Police Department)

Criminal defense attorney Stuart Kaplan said Tuesday that law enforcement likely gleaned much more information from the autopsy than it has made public and is likely able to either exclude Brian Laundrie, who has been named a person of interest in the case, or connect him to his former fiancée’s death. 

"Generally when there’s a strangulation, when someone is acting out in a rage of violence, the victim will try to fend off that attacker. Oftentimes, there is DNA transfer — most of the time it will be under the fingernails, where someone is trying to claw someone or scratch someone," Kaplan told Fox News. "Those transfers of DNA will either rule in Brian Laundrie or potentially could exclude him."

GABBY PETITO AUTOPSY: CAUSE OF DEATH WAS STRANGULATION, TETON COUNTY CORONER DR. BLUE SAYS

The FBI went to Brian Laundrie’s family’s home in North Port, Florida, on Sept. 26 to compare DNA.

"The FBI requested some personal items belonging to Brian Laundrie to assist them with DNA matching and Brian’s parents provided the FBI with what they could," Laundrie’s lawyer, Steven Bertolino, told Fox News last month. 

Eiglarsh noted that even if Laundrie's DNA is found on Petito's remains, it would have to be in unique places to implicate him since he wasn't a stranger and some of his DNA would be expected on her body. 

Laundrie has not been charged with a crime in Petito's death and is only a person of interest. He is wanted for unauthorized use of a debit card that belonged to Petito between Aug. 30 through Sept. 1. 

Petito's remains were found on Sept. 19 at a campground in Wyoming about three to four weeks after she was killed, which would place her death around the last week of August. 

The couple set out on a cross-country road trip in June, but their relationship became strained as the weeks passed, with Petito's mom telling investigators that her daughter described how there "appeared to be more and more tension between her and Laundrie," according to a search warrant.

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Petito and Laundrie were involved in a domestic incident on Aug. 12 in Moab, Utah. A witness told police that a "gentleman was slapping the girl" and Petito said that Laundrie "grabbed" her face, but she also told officers that she slapped him. The two were separated for the night and no charges were filed. 

First-degree murder is punishable by death or life imprisonment in Wyoming. Homicide can also result in manslaughter, second-degree murder and other charges.