FORT WORTH -- A participant in the Valero robbery that resulted in the death of two men in 2010 told a jury Wednesday that his friend, Randy Seibel, spent weeks helping to plan the crime.Seibel, 38, is on trial for capital murder and faces an automatic sentence of life in prison without parole if convicted, according to prosecutors Sean Colston and Kevin Rousseau.Seibel is accused of participating in the killing of Jerry Burnett, a 70-year-old Mrs Baird's delivery driver, and Daniel Rojas-Torres, a convenience store clerk. Kwame Rockwell, a co-defendant in the case, was convicted and sentenced to death in January. Prosecutors are not seeking the death penalty in the Seibel case.Chance Smith, 25, the fifth co-defendant in the Valero robbery, testified that the car business Rockwell was part owner of was failing and the robbery was an attempt to put the dealership back on solid financial footing.Smith pleaded guilty to a reduced charge of aggravated robbery and was sentenced to 20 years in prison in exchange for his testimony, Rousseau said. Seibel, Smith and Rockwell were all friends who worked at the same car lot next door to the Valero gas station they robbed."It was one of the busiest gas stations I've ever seen," Smith testified. "I cashed my income tax check there. About $5,000."The Valero robbery evolved from idle chatter to elaborate plans that included staging an accident and setting the store owner's home on fire with homemade napalm, Smith told the jury.The men used the store owner's license plate number to obtain his home address, Smith said. The subdivision where the store owner lived had only one entrance, and Seibel, Smith and Rockwell plotted to use two vehicles to track him and cause an accident on a deserted street, Smith testified.They planned to strike after the store owner left the bank with cash to stock his convenience store, Smith said. Rockwell was supposed to hit the store owner's vehicle with his Ford pickup and use a 9 mm handgun to rob the store owner after he got out of his vehicle, Smith said.But the collision never happened, Smith told the jury."We all followed him, but we ended up losing him at red lights," Smith said.When that plan went awry, the men changed plans. Rockwell told his friends the store owner might be keeping money at home to avoid paying taxes, Smith testified. He said he watched the store owner's children walking in the store with empty bags and coming out with full bags, and said those bags might be filled with money.Rockwell said if the store owner's house caught fire, he might be forced to bring that money to the store, Smith testified. Seibel told his friends he knew how to make homemade napalm with peanut butter and lighter fluid. But when they tried to make the napalm in the rear of the car lot, the concoction would not catch fire.Smith said the men changed the formula, using gasoline and used oil to make the napalm. But that plan failed, too, Smith said."He [Rockwell] said he threw one and it did not catch fire and he had thrown another on the roof and tried to catch that on fire but someone yelled at him and he ran away," Smith saidThere were at least two attempts to rob the store that failed because the store was too crowded, Smith testified. On March 23, 2010, the men attempted another robbery, which resulted in the deaths of Burnett and Rojas-Torres, according to testimony.Smith told jurors that when he got home, the robbery was on television. He said he learned then that one man was killed and another wounded.Rockwell said he only got a few thousand dollars from the robbery even though he expected more than $100,000, Smith said.