Police are searching for the murder weapon used to kill a Spring Valley teenager. Investigators say 22-year-old Ryan Ross told them he used a baseball bat to beat 16-year-old Karesse Ebron to death after she told him she was pregnant with his child. But investigators have not been able to find the weapon. Police say Ross told them he ditched Ebron?s cell phone and car keys in the Pascack Brook, along with the bat. Police found the phone and keys, but not the bat. Investigators say they are looking for a black composite-type bat, the size used by Little League ball players. Cops say a witness spotted the bat floating in the Pascack Brook. Police are appealing to the public for help. Anyone with information is asked to call the Ramapo or Spring Valley police at 914-357-2400 or 914-356-7400 .