Third Arrest in Teen Double Murder

There has been a third arrest in the case of the two Atlanta girls caught on Tybee Island and charged with a double murder outside Atlanta.

Yesterday, Sandra Ketchum, 16, and Holley Harvey, 15, pleaded guilty to killing Harvey's grandparents near Atlanta last August. Both were given life sentences.

Today, there has been another arrest in the case. Calvin Lawson, 37, was arrested for giving the girls crack and marijuana before the murders were committed.

Police say Lawson is also responsible for what happened because under Georgia law committing a felony that leads to murder is grounds for a murder charge.

Police tracked the girls down on Tybee Island one day after the murders.

Reported by: Nicole MacMillan,