A 32-year-old Philadelphia engineering apprentice convicted of dealing crack cocaine and tampering with a witness has been sentenced in U.S. District Court to 13 years in prison.

After he was indicted on federal drug charges, Daniel "Danny White" Harrison threatened a federal informant, telling the informant to take responsibility for drugs found in Harrison's home, authorities said.

Philadelphia police arrested Harrison in 2004 after he sold crack to a police informant. During a search of his home, police said, they recovered 175 grams of powder cocaine, 88 grams of crack cocaine, a scale, and $93,000 in cash.

The case was soon referred to federal authorities.

In 2005, defense lawyers provided a signed statement in which the informant took responsibility for the narcotics. After investigating, federal authorities said, they determined that Harrison had threatened the informant and his wife at gunpoint.

Harrison was convicted on the drug-trafficking and witness-intimidation charges at a trial in June.

Assistant U.S. Attorney Derek Cohen had sought a term of 171/2 years at Harrison's sentencing Monday by Judge John Padova.

Cohen said Harrison was "a major drug dealer" and once had sold crack during a child's birthday party. The witness intimidation, Cohen said, "was outrageous and threatened the very core of the justice system."

In a filing to Padova, Harrison said he was a first-time offender and the loving father of seven children. He said he took "full responsibility" for his mistakes.

Contact staff writer John Shiffman at 215-854-2658 or jshiffman@phillynews.com.