The teen accused in the killing of a 70-year-old man last summer is going to prison - for another crime.

Romeo Williams got the maximum sentence of 15 years in prison on an unrelated gun charge.  He was convicted in June.  Williams is also accused delivering the fatal blow that killed James Gifford last September.  Gifford was killed just outside a Valley Drive 7/11 location.  Williams is only facing a manslaughter charge in the death of Gifford because DA Bill Fitzpatrick says Williams' single punch didn't rise to the level of murder.