Everyone knows that smoking kills. But in the case of on confessed cartel hit man, it also helps catch killers.

Authorities in Central Florida said DNA from a cigarette butt found inside a soda can helped detectives solve a 2006 murder and possibly a slew of other murders after the suspect, Jose Martinez, admitted to the gruesome murder and as many as 30 more slayings.

Sheriff's investigators from Florida’s Marion County charged the 51-year old Martinez with premeditated first-degree murder in the deaths of Javier Huerta and Gustavo Olivares-Rivas after traces of his DNA were found inside a Mountain Dew can. The can had been left inside of a Nissan Titan 4 pickup where the bodies were found on Nov. 8, 2006.

Martinez, who claims to be a hit man for a Mexican drug cartel, said that he killed the two men because they stole 10 kilograms of cocaine “from another guy."

"If I didn't do the job, someone would have," the remorseless Martinez said, according to the Orlando Sentinel.

Capt. James Pogue with the Marion County Sheriff’s Office told Fox News Latino authorities have confirmed 11 of his murders. All of them were done for an unidentified Mexican drug cartel.

The people Martinez killed supposedly were also working for the cartel but went rogue and instead decided to keep huge loads of cocaine for themselves, Pogue said.

So Martinez would track them down, lure them using a ruse such as offering them work and then force them at gun point to come up with the money they owed the cartel.

But even after collecting the dues, said Pogue, Martinez killed them – because he feared if he let them go, one of them could possibly later identify him.

“To find a criminal of this caliber, and the way it was done, it’s something else,” said Pogue. “The way we were able to track him down is through DNA from a fingerprint he left on a Mountain Dew can in one of the victim’s trucks.”

Martinez was recently arrested in Yuma, Arizona, and then extradited to Alabama, where he was wanted on first-degree murder charge. It was there that he admitted to killing the two men, and then confessed to the other murders.

"I've killed over 30 people,'' he said, adding that he began his murder spree when he was 16 years old.

Saying only that it was time to pay for all the things he had done, Martinez did not reveal who hired him to commit the double homicide.

For the two victims in Florida, Martinez told investigators that they did masonry work and he posed as a new home buyer who wanted an estimate on some housework. Martinez then pulled out two 9mm handguns with 15-clip magazines and made Olivares-Rivas call his wife to retrieve money from a backyard safe.

After torturing Olivares-Rivas, Martinez made the two men tie each other up and then shot them, he told police. He claims to have retrieved $170,000 from the home of Olivares-Rivas and another $40,000 from the pickup.

Martinez claims to have remembered smoking cigarettes but thought he had cleaned up all the butts before he left the car.

Pogue said in his confession, Martinez did not reveal many details on his cartel work.

“He just said he worked for them, but he didn’t really say his actual occupation, or how close he was to them, or which cartel he actually worked for,” said Pogue. “He didn’t want to give us any names.”

Pogue said Martinez is originally from Mexico but has legal status in the U.S.