A San Francisco gang member convicted of murder for ordering an attack on an innocent man he mistook for a rival was sentenced to 15 years to life in prison today. Jonathan Johnston, 30, a reputed Norteno shot-caller nicknamed “Savage,” was convicted in June of second-degree murder and gang participation for his role in a vicious knife assault on 29-year-old Carlos Urzua outside Urzua’s Mission District home on the night of Nov. 25, 2006.Royale LeBlanc, 23, nicknamed “Crazy Teno,” was convicted of first-degree murder, gang participation and robbery for stabbing Urzua 18 times and stealing his cell phone.Urzua, a single father of a 10-year-old girl, who lived with his father and younger brother at the home, had no gang affiliation. He bled to death in his father’s arms.LeBlanc was sentenced last month to 28 years to life in prison.Prosecutor Scot Clark said today that Johnston, LeBlanc and other gang members “were in search for a victim that night” and followed, in their car, another car in which Urzua was riding.Johnston reportedly mistook Urzua for a rival Sureno.When Urzua was dropped off outside his home, Johnston told LeBlanc, “There’s a scrap, go get him,” according to a young witness, a prospective gang member who was in Johnston’s car at the time but decided to testify at trial against the men.Urzua was surrounded by two to three men, including LeBlanc, on the steps of his home as Johnston drove off, returning to the scene to pick up his comrades after the killing, according to Clark.”This was a wolf pack murder,” Clark said.Police arrested Johnston and LeBlanc after they inexplicably drove back to the area of the crime a second time. Johnston wept briefly during today’s sentencing hearing, after his sister pleaded for clemency from Judge Jerome Benson.In a terse statement of his own, Johnston expressed condolences to Urzua’s family for their “tragic loss,” he said.His attorney Brian Petersen asked Benson to sentence him only to probation, arguing Johnston “didn’t personally intend for anyone to get killed.”Petersen acknowledged that Johnston had multiple prior convictions for drug sales and violating his probation, for which he served multiple prison terms, but noted that this was “his first violent crime.””This defendant is not worthy of any mercy on the part of the court,” Clark responded.Clark said Johnston chose to become a gang member.”That course destroys lives,” he said.Benson denied probation and sentenced Johnston to 15 years to life for the murder charge. An additional three-year sentence for gang participation will run concurrent to that sentence.”This was a group of gang members on the prowl for the weak, the vulnerable and the defenseless,” Benson said.Benson said the evidence showed Johnston “played an active role” in the crime.