A string of hate messages received by a Hindu family in the US have been traced to the couple's teenage son.
The motive for the 17-year-old sending the messages to his own family in Wayne city of New Jersey was not immediately clear but investigators said computer analysis helped police and FBI to trace the culprit.
"My heart is breaking right now. I can't figure out why my son would do something like that," the teenager's father told the Bergen Record newspaper.
County Prosecutor James F Avigliano said they had suspected the son's involvement almost from the beginning but needed to gather proper evidence.
Avigliano said the boy recruited several friends to help with his campaign, which began with a series of hate letters in January this year.
"We Kill U," "We will fire your house," "Watch Your Kids," were among the handwritten messages received by the family. Some messages were also spray painted on the family's property.
The South Asian community in the town had been enraged after the family received the messages and demanded that the culprits be brought to justice.
Avigliano said a series of threatening e-mails sent after May 2006 were traced to the accused after Prosecutor's Office detectives seized his computer on Monday.
The boy had attempted to delete his e-mail files, but detectives were able to scan the computer for a full history of recent online activities, the prosecutor said.