Two teenagers who teamed up with a third to commit a string of robberies in the fall of 2005 began long prison terms Friday.

Alonzo Blake and Michael Yarbray, both 19, had bright futures, their attorneys said in U.S. District Court. Both did well in school and both worked after-school jobs. Mr. Blake was already in college after graduating high school with honors.

But for several months in the fall of 2005, the two teens and Jeremiah A. Lane, 20, decided for reasons they couldn't define Friday that they would rob a number of south Augusta businesses.

Although the businesses were not federal institutions, crimes involving commercial establishments or weapons can be prosecuted in state or federal court.

While Mr. Blake or Mr. Lane served as drivers and lookout men, Mr. Yarbray pulled on a mask and went inside the business with a gun. Anyone present was forced into walk-in freezers, bathrooms or to the floor.

At the last robbery Nov. 21, 2005, Mr. Yarbray fired the weapon.

"Seventeen- and 16-year-olds simply don't use the same judgment we would use," said Mr. Blake's attorney, Michael Garrett.

Anyone would agree the case was lamentable, U.S. District Judge Dudley H. Bowen Jr. said, but it was also reprehensible.

Because of mandatory minimum sentences for firearms and the use of firearms, prison sentences for both teenagers increased.

Mr. Yarbray was sentenced to 216 months and Mr. Blake was sentenced to 147 months. Mr. Lane's sentencing was postponed.

Their sentences were increased by 10 years and five years, respectively, because of the gunfire in the last robbery. Mr. Yarbray's sentence was greater because he fired the gun, but Mr. Blake's increased because he also was involved in the crime.