A man from Houston who allegedly shot and killed his girlfriend in December 2006, and on the run for more than a decade, was arrested Tuesday in Nacajuca, Mexico.

A missing toe helped authorities confirm 52-year-old William Joseph Greer's identity. 

Greer is accused of killing his 28-year-old girlfriend Tammy Marie Esquivel in Harris County, Texas, some 11 years back.

A murder warrant was issued for Greer in January 2007, and he was indicted for the murder in March of the same year. He was added to the United States Marshals’ 15 most wanted fugitives list in 2016.

A bounty of up to $25,000 was also offered for information leading to Greer’s arrest.

A joint operation by the U.S. Marshals Service, the Harris County Sheriff's Office, and Mexican authorities helped the authorities track down the most wanted offender in the far-flung city in the southern Mexican state of Tabasco.

Greer, who was nicknamed “chameleon,” by the authorities, has a missing toe on his right foot — a unique characteristic that was widely publicized when he first went missing in 2006.

According to a report in Houston Chronicle, Chief Deputy U.S. Marshal Richard Hunter said, “He’s been a chameleon for 11 years.”

According to the New York Daily News, during a press conference Wednesday, a U.S. Marshal said, “As we approach the 11th anniversary of Tammy’s murder, we hope that this arrest brings Tammy’s loved ones some sense of closure.”

Greer will be investigated by the Harris County Homicide Division after his return to the U.S., reported the NY Daily News.

In a release on the official website of the U.S. Marshals Service last year, Greer was described as 5-foot-10 white male weighing approximately 220 pounds, with brown hair and green eyes.

His distinctive physical characteristics included scars on his left forearm and left thigh, and a missing toe on his right foot.

According to a report in the CNN, Greer's girlfriend Esquivel was working as an exotic dancer when she met Greer at her workplace. Before moving in with Greer, she divorced her husband.

The couple had a stormy relationship, and things came to a head in December 2016, when police in Liberty County, Texas, were called to the scene of a pickup truck parked in a ditch.

They found Esquivel's pink cell phone in the vehicle. Suddenly a ranting Greer appeared at the scene wearing only a shirt, telling police it was his vehicle.

He went on and on about how much he loved Esquivel, her death and a gun that "just went off."

Greer was booked for public intoxication, but he made bail and immediately fled the state. Later Greer's young sons told authorities that they had overheard Greer and Esquivel arguing, followed by gunfire.

Esquivel’s body has never been recovered.

In the last ten years, Greer had allegedly been spotted in Louisiana and Kentucky, reported the CNN.