A second man arrested in connection with what is believed to be Dallas’ largest armored car heist ever has agreed to plead guilty.

The decision by Donald Ray Williams to sign plea papers Monday means a third conviction for him and his longtime accomplice, Freddy Lee Foots.

The men, both 53, served prison sentences for robbing another armored car in 1988 in downtown Dallas. They also robbed a bank together a few years prior, authorities said.

Their latest heist was on was Sept. 5, 2007, when they stole $1.9 million out of a Loomis armored car at the Compass Bank near the Lakewood Country Club in Lakewood.

Williams faces up to 20 years in prison for the robbery, but he could get up to life in prison for using a gun during the holdup. He faces a fine of up to twice what he stole. Williams was arrested March 15 in Rosebud, Texas, after the FBI posted pleas for tips on digital billboards in the area.

FBI agents are still gathering evidence on one other accomplice, and possibly more, prosecutor Rick Calvert said.

Foots, of Dallas, was convicted last year in the Lakewood robbery. He received nearly 30 years in prison and was ordered to pay $1.3 million in restitution. He was nabbed within days of the robbery following a high-speed West Texas car chase.

Williams eluded the FBI for 18 months. Authorities decided to use billboards on Interstate 30 in Grand Prairie and Arlington to gather tips.

It paid off. Tips led them to Williams in Rosebud, south of Waco. They found $9,000 in stolen cash in a house he was using there, and an additional $27,000 inside a San Antonio apartment.

In court papers, Williams admits that he and others watched the Compass bank in the weeks leading up to the 2007 robbery to become familiar with the armored car’s schedule. He also took note of the guards’ routine, papers show.

After the heist, the robbers divided the loot. Williams’ share, according to court papers, was $300,000.

Williams bought a BMW for himself, a Volkswagen for his girlfriend, as well as clothing, shoes and other items, court documents show.

Just before the 2007 robbery, the pair was released from prison. Williams had served about 15 years and Foots about 18 years for a $1.1 million armored car heist in Uptown in 1988. They were arrested after going on a spending spree at Neiman Marcus.

Before that, in the early 1980s, the pair was convicted of robbing a bank together, prosecutors said.