BRISTOW, Oklahoma - The Creek County District Attorney has dropped charges against a former Bristow Walmart manager suspected of organizing a heist of his store.

The DA’s office tells News On 6 that Rico Robertson suffered a massive stroke and has been declared incompetent to stand trial.

On July 4, 2015, a man went to Walmart claiming to be a Loomis armored truck driver and an employee handed him a deposit of more than $70,000, investigators say.

7/4/2015: Related Story: Man Poses As Armored Truck Driver, Steals $75K From Bristow Walmart, Police Say

That man, later identified as Bryan Jervante Johnson, of Bakersfield, California, left the store in a SUV driven by Mariah Bustamonte, according to the Oklahoma State Bureau of Investigation.

Bustamonte is Robertson’s stepdaughter. OSBI says Johnson is a distant relative of Robertson's and was recruited to carry out the heist.

Bustamonte was arrested and charged with conspiracy and embezzlement.

Documents say Bustamonte was given $900 “so she wouldn’t turn herself in.” During the investigation, agents said they were told Johnson's clothes were burned in a charcoal grill before he left Tulsa.

Robertson’s wife, Monica, is believed to have known about the robbery beforehand and destroyed evidence, investigators say. She also was arrested and faces a conspiracy charge.

Authorities say Rico Robertson drove Johnson to a Tulsa bus station after the robbery. At last check, Johnson still was at large. At the time of the robbery, he also was wanted in California for several robberies and a shooting.

7/15/2015: Related Story: Court Documents Provide Insight Into Bristow Walmart Heist