A Vancouver man who assaulted his 3-month-old son, causing 15 rib fractures, was sentenced Wednesday to about 2 1/2 years in prison.William Jeffrey Burleson, 37, previously pleaded guilty in Clark County Superior Court to second-degree domestic violence assault of a child.According to an affidavit of probable cause, Julia Durr brought her 3-month-old son, identified in court records as JD, to a hospital out of concern that his ear was swelling. Clark County sheriff’s deputies responded to Randall Children’s Hospital at Legacy Emanuel Medical Center in Portland and learned that JD had 15 rib fractures and a partial laceration on his liver.Durr told authorities that she was worried Burleson was too rough with JD, the affidavit states.In an interview, Burleson told investigators there were times he hugged JD tightly and squeezed his ear but said he did not try to intentionally hurt the boy. When the deputy pointed out that there were multiple injuries inflicted over a few weeks and that not all of them could be accidental, Burleson claimed there were times when he was “tired and half-asleep and might not realize what he is doing,” according to the court document.On Wednesday, Burleson’s attorney, David Kurtz, told the judge that his client admits to hurting the boy, but it wasn’t intentional. He said Burleson lacked parenting skills and that many of the child care duties had fallen on him.Judge Robert Lewis accepted the attorneys’ previously agreed-upon sentencing recommendation of 31 months in prison followed by 18 months of community custody. Burleson will also have to undergo a parenting class and an anger management evaluation. He is not to have contact with his son.