A teenager who at age 14 was the youngest person ever charged as an adult in San Mateo County told fellow gang members from jail to scare witnesses who were supposed to testify in his murder case, which ended in a mistrial, prosecutors said Friday.

Five alleged Sureño gang members have been charged with conspiring with Josue Raul Orozco, now 19, to intimidate witnesses into changing their testimony or not testifying at all, authorities said.

The suspects and a 17-year-old girl were arrested Wednesday. They appeared in court Friday but did not enter pleas.

Orozco is accused of killing 21-year-old Francisco Rodriguez outside the victim's Redwood City home on July 12, 2005. Prosecutors say Orozco and Rodriguez were in rival gangs. Orozco, an alleged Sureño gang member, denies he was the shooter.

The jury in his murder case deadlocked in December after a 24-day trial and six days of deliberations. Prosecutors intend to retry him.

Prosecutors began uncovering evidence in December that Orozco and other suspected Sureño members had contacted and dissuaded witnesses in his trial, said Assistant District Attorney Karen Guidotti.

"Orozco orchestrated this conspiracy from the San Mateo County Jail, where he called numerous Sureño members on the streets and directed them to either prevent witnesses from attending the trial or scare the witnesses into altering their testimony," Guidotti said.

Orozco escaped from the San Mateo County juvenile lockup in 2008 but was arrested seven months later in Texas.

On Wednesday, law-enforcement officials from numerous agencies raided locations in Redwood City, East Palo Alto and Oakland to arrest the suspects in the conspiracy case, Guidotti said.

Besides Orozco, who has remained in jail since the mistrial, the adults who were arrested were Bianca Aguillon, 19, and Arturo Becerra, 19, both of East Palo Alto; Cesar Ponce, 20, of Redwood City; and Edgar Cibrian, 20, whose hometown is unknown.

The four suspects were charged with witness intimidation, felonies committed for the benefit of a criminal street gang and conspiracy to intimidate witnesses.

Another alleged Sureño member, Alexandro Stephen Villar, 19, of Redwood City, has been charged but is still being sought.

Charges against a sixth defendant, Eduardo Lopez, 19, were dropped for lack of evidence.