DNA testing and the confessions of a complicit bank teller have tied a group of rappers known as the Truce Mob to a robbery in New Orleans last year in which two masked men stormed a Chase Bank branch in Gentilly Terrace and stole nearly $200,000 from the safe, according to court documents.

The young men — some of whom were implicated in the high-profile robbery of a jewelry store in Gonzales over the summer — spent tens of thousands of dollars of the loot on marijuana and the production of music videos, according to authorities.

The robbers burned the getaway car but failed to cover their tracks completely, according to the FBI, which said one of the gunmen used an ungloved hand to drag a bank employee to the safe during the December 2014 heist.

The State Police Crime Lab tested that employee’s jacket, according to court filings, and found forensic traces of Walter J. Johnson, a 33-year-old ex-convict who has served prison time for armed robbery and more recently was charged in the jewelry store stickup in Ascension Parish.

But the FBI caught perhaps its biggest break with the cooperation of Zoe Williams, a teller at the New Orleans bank who at the time of the robbery was dating Johnson’s brother, Casey Johnson, the alleged getaway driver.

Williams told investigators that Walter Johnson and one of his friends, Jay Lyons, approached her about a week before the heist and that she revealed to them several details about her bank’s operations, including “the procedures for opening the vault,” Special Agent Christopher Bauer wrote in a criminal complaint.

What’s more, court records show, Williams admitted knowing her boyfriend planned to drive his brother and Lyons to the bank.

The robbery happened about 8:30 a.m. Dec. 20 at the Chase Bank at 3231 Gentilly Blvd. Two men, armed with handguns and wearing hoods and face masks, encountered Williams as she walked into the bank. A second bank employee — the woman whose jacket contained the DNA evidence — was already inside.

“One of the robbers demanded the tellers go to the safe and open it,” Bauer wrote in the criminal complaint.

The masked men placed $196,715 in a black gym bag and left the bank, running through the parking lot. Williams, in an interview with the FBI, said she recognized the voices of Walter Johnson and Lyons during the heist. She said she also knew the men fled to Houston with her boyfriend later that day, court records show.

Four days later, on Christmas Eve, Casey Johnson passed through New Orleans on his way to Atlanta, stopping at his father’s home in Chalmette. Williams told the FBI she met her boyfriend at the Chalmette house and that he showed her “his cut of the money and offered her some, but she did not take any,” the criminal complaint says.

Williams alleged that Casey Johnson “described waiting on a side street next (to) the bank after dropping off his brother and Lyons” to commit the heist. He allegedly told Williams he had been worried someone might have spotted him picking up the gunmen as they fled the bank.

Williams does not appear to have been charged in the robbery.

Casey Johnson was arrested on a parole violation in Kenner in August and, in an interview with the FBI, denied involvement in the bank robbery but claimed Walter Johnson and Lyons had used his vehicle during it.

Another critical turn came when the FBI went to the Ascension Parish Jail in Donaldsonville to interview Jaquandes Octave, 21, who admitted his role in the July jewelry store heist. Octave said he had learned several details about the bank robbery and identified a fourth man, Ryan Johnson, who he said remained in the getaway car.

He also told the FBI that a flash drive seized from Casey Johnson’s vehicle by authorities in Atlanta had video of the group “counting money from the bank robbery,” according to FBI records.

According to Gonzales police, Walter Johnson, Lyons, Octave and a 14-year-old boy went to Roussel’s Antiques and Fine Jewelry on July 14 under the guise of having a broach or pendant repaired and robbed the Ascension Parish store of $160,000 in jewelry and $1,200 in cash. Police identified the men and their getaway vehicle through surveillance cameras, license plate readers and social media posts, according to a police report.

The gunmen entered the store in the 1400 block of North Airline Highway and ordered several employees to lie on the floor while one man put a gun to the head of an employee and demanded he retrieve surveillance equipment from the office, according to the report.

At one point, the teen was heard urging the others to shoot the employees, saying, “Let’s pop them, let’s pop them,” but one of the others said they were not going to hurt anyone.

After the robbery, the Johnson brothers, Lyons and Octave ended up in Atlanta to shoot a rap video for their group, Truce Mob. One of their videos on YouTube, “I’m just sayin’,” features Walter and Casey Johnson and Lyons, the report says.

In one of their songs, uploaded to YouTube, the group vows to “get rich or die trying.”

Casey Johnson was pulled over in Atlanta days after the Gonzales robbery and found with a large amount of jewelry from Roussel’s in the vehicle.

Prosecutors in Ascension Parish charged the three adults alleged to have committed the robbery and Casey Johnson with four counts of armed robbery.

Walter and Casey Johnson and Octave also were charged with being felons in possession of a firearm.

Follow Jim Mustian on Twitter, @JimMustian.