South Fayette police arrested a second suspect yesterday in connection with a teenager's attempt to kill family members by planting bombs in his family's South Fayette home.

Thomas J. Moore, 18, of South Park, turned himself into authorities about 10 a.m., said South Fayette police Chief Louis Volle, and was arraigned on charges of criminal conspiracy and hindering apprehension.

According to a criminal complaint, he transported chemicals and bomb-making materials to Christopher Janney, 16, and served as a getaway driver. Mr. Janney, who has been charged with attempted homicide and criminal conspiracy, allegedly placed homemade bombs near the heads of family members while they slept in the home on Dutch Hill Road.

Investigators targeted Mr. Moore after searching through Mr. Janney's text messages and communications through MySpace.com.

Chief Volle said police are likely to charge a third co-conspirator in the coming days.