[When we visited the home, Rodger’s girlfriend’s family explained how they learned about the horrific murder. They say he confessed to the killings earlier this week, and even pointed her to where he hid the evidence."Evidently quite a bit of evidence. He brought it all here and threw it away and told Taylor where it was. I think they found the bloody jumpsuit he wore," said Cathy Gaston, a family member.
His girlfriend then told investigators when they moved in for an arrest.
http://www.nbc-2.com/story/29893142/missouri-man-to-be-charged-with-sievers-murder#.Vd95i9NVhHw
Not sure I understand this. Sounds like the gf only told police where the evidence was hidden when they showed up to arrest him.