PHILADELPHIA - An 11th-grade student from East Germantown pleaded guilty in Philadelphia Family Court on Wednesday to using his Twitter account to intimidate the victim in a 2012 attempted shooting case in the city's Southwest section.

Nasheen Anderson, 17, a student at Martin Luther King High School, pleaded guilty to intimidation of a witness and terroristic threats before Administrative Judge Kevin M. Dougherty.

Anderson's plea came after Dougherty denied a motion by the District Attorney's Office to have him tried as an adult.

Police initially believed Anderson might have been linked to an anonymous Instagram page that for months identified witnesses to violent crimes across the city to "expose rats," law enforcement sources said.

Investigators looked for a connection between him and a defunct Instagram account called rats215, which regularly posted witness' photos next to statements they gave police. Photos of a witness statement on Anderson's Twitter account later appeared on rats215, leading police to suspect a connection.

The District Attorney's Office said in a statement Wednesday that Anderson had not been charged in connection with the rats215 account, which they said was "completely different" than the Twitter account Anderson had used.

Prosecutors said that the rats215 investigation was continuing, but that Anderson had not been accused of involvement in that case.

In the intimidation case in which Anderson was convicted, Assistant District Attorney Jan McDermott said she would ask for "a significant period of confinement" to a juvenile treatment facility when he is sentenced Dec. 16.

Juveniles adjudicated as delinquent may be placed in a juvenile facility until they are 21. Anderson has been in custody since Nov. 12, when he was pulled out of class.

McDermott said the intimidation count was a first-degree felony: "He could be facing three to six years if he were an adult."

Police said Anderson used his Twitter account to post a photo of the victim and copies of secret documents that were presented to a grand jury investigating the attempted shooting.

Anderson is the latest in a series of people arrested for using social media to try to discourage crime victims or witnesses from cooperating with authorities.

District Attorney Seth Williams has said witness intimidation has "reached near-epidemic levels" in the Philadelphia criminal justice system.

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