South Fayette police have charged a third suspect in connection with a teen's alleged attempt to kill family members by setting off bombs in his house.

Police issued a warrant for Eric Evans on conspiracy charges, saying he aided a plot by 16-year-old Christopher Janney. 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.

Police also arrested Thomas J. Moore, 18, of South Park, on Monday on conspiracy charges connected with Mr. Janney's scheme.