DOVER, Del. — A former airman at Dover Air Force Base has been given 18 months of probation in the death of a 21-month-old boy who was left in his care while his mother was deployed overseas.

Justin Corbett, who had been charged with first-degree murder in the 2012 death of Evan Dudley, was convicted in July on the lesser charge of criminally negligent homicide.

The judge suspended a maximum eight-year prison sentence for 31 days time served and probation, citing Corbett’s lack of a criminal background and his exemplary military record.

Prosecutors, along with the victim’s mother, had asked the judge to sentence Corbett to eight years behind bars.

Corbett maintained that the boy accidentally fell down a set of stairs after being left alone briefly with another child.