RALEIGH - A second teenager accused of taking part in the 2008 overdose and beating death of Matthew Silliman, an Eagle Scout from Apex High School, admitted to participating in the crime.

Aidil Khan pleaded guilty in Wake County Superior Court last week to second-degree murder, attempted first-degree murder and two counts of conspiracy.

On Aug. 13, Allegra Dahlquist entered a similar guilty plea to second-degree murder and conspiracy charges in the death of Silliman, whose body was found in late November 2008 at a vacant mobile home owned by Dahlquist's parents.

Prosecutors say Khan and Dahlquist were among a group of teenagers who drove Silliman around Wake County before binding his arms and legs with zip ties, stretching duct tape across his mouth and wrapping a bag around his head.

Silliman's body was found in a sleeping bag, according to a medical examiner's report. His head had been beaten with a hammer, investigators said.

The lead suspect in the case, Ryan Hare, 19, pleaded not guilty to first degree murder and other charges this month - the same day Dahlquist entered her guilty plea. Prosecutors and defense attorneys have acknowledged that a fourth teen charged in the case, Drew Shaw, has been offered a plea arrangement similar to that offered to Khan and Dahlquist.

Hare's trial is set for mid-September.