Andrew Cooper Esslinger, 27, pleaded guilty in April to conspiracy to commit robbery, possession of narcotics for sale and possession of a firearm during a narcotics sale in exchange for the six-year term.
He testified against former Santa Rosa and Santa Rosa Junior College police officer Robert Starling, 35, of Windsor, who was sentenced to 30 years and four months in prison in connection with four robberies in Sonoma and Marin counties between 2007 and 2009.
Esslinger acknowledged he had a cocaine problem at the time of the robberies but told Judge Arthur Wick he did not want to use that as an excuse for his behavior.
"I wish I could rewind time and make other choices," he said. "I forgot who I was the last few years. Since my arrest, I did everything in my power to make things right."
Esslinger thanked the district attorney's office for offering the plea agreement.
Wick acknowledged Esslinger's cooperation with the prosecution of Starling and praised him for his articulate and truthful testimony.
"This gentleman is certainly worth saving," Wick said. "You've done what is right and were truthful even to your detriment."
Esslinger acted as a lookout at two of the robberies in Novato and Sebastopol and helped Starling plan them.
With credit for time served in Sonoma County jail, Esslinger will serve less than four years in prison.
At his trial, Starling, who had also worked as a driver for the Brink's Company, testified he used a fake air pellet gun and depended on the element of surprise to rob the armored car couriers. The plan was to complete the robberies and escape in less than 10 seconds, he said.
He was convicted May 4 of seven felony counts of robbery, conspiracy, intimidating a witness and personal use of a weapon enhancements and three misdemeanor charges regarding falsely reporting a crime and wearing a mask.
During the Novato robbery on April 15, 2009, Starling called Novato police to report a kidnapping attempt to distract police.
He also called Rohnert Park police on March 18, 2009, to report a person with a gun was on the campus of Rancho Cotate High School, although there was no bank robbery in Rohnert Park that day.
