HUNTSVILLE - One 16-year-old drove drunk, ran a red light and crashed into a pregnant woman's car, killing her and her unborn child.

Another drunken teenager rammed a pickup truck into a crowd of people assisting a stranded driver, killing four.

Jaime Arellano went to prison. Ethan Couch went free.

The stories of the two Texas teens illustrate how prosecutors' decisions in similar cases can lead to wildly different outcomes. The poor immigrant from Mexico has been behind bars for almost a decade. The white kid with rich parents got 10 years of probation.

Arellano becomes eligible for parole next year. Couch faces possible detention for violating his probation when he returns to court Feb. 19. Depending on the judge's ruling, he could get three months in jail and adult probation.