A former BP engineer was sentenced Wednesday to 10 months' probation for a misdemeanor pollution charge connected to the 2010 Gulf of Mexico oil spill.

Donald Vidrine had served as a rig supervisor on the Deepwater Horizon offshore rig. Prosecutors had argued that he and one-time co-defendant Robert Kaluza botched a pressure test before the rig's explosion, which sent millions of gallons of oil spewing into the Gulf.

Both had once faced manslaughter charges connected to the deaths of 11 rig workers. But prosecutors backed away from those charges last year, and pursued the misdemeanor Clean Water Act charge instead.

Kaluza chose to go to trial and was acquitted in February. Vidrine pleaded guilty under an agreement that called for probation. He stood quietly and had no comment as U.S. District Judge Stanwood Duval formally sentenced him.

Vidrine's sentencing and Kaluza's February trial bring an end to a series of spill-related criminal cases that largely unraveled for federal prosecutors.

The government did secure a landmark criminal settlement and record civil penalties against the corporation, which BP said would cost it billions of dollars.

But federal prosecutions of four former BP employees ended in acquittals or plea bargains for lesser offenses that resulted in no prison time.

Former BP executive David Rainey was acquitted last June of manipulating calculations to match a far-too-low estimate of the amount of oil spewing into the Gulf.

Once charged with obstructing a federal investigation by deleting text messages, former BP engineer Kurt Mix made clear that he felt he had been charged unjustly and that he felt vindicated when he ended years of prosecution by pleading guilty to a lesser charge last year. He was sentenced to probation.