LINCOLN, Neb. (AP) — Police say a map sent by a prisoner awaiting trial in a fatal shooting earlier this summer led police to what could be the murder weapon.

Police believe Danny Tucker Jr., charged with first-degree murder for the June 20 shooting death of Earl Richardson III, sent a card from jail to a friend that included a map of the grounds of a Lincoln apartment complex.

Police took the map, followed its instructions and found a .357-caliber handgun buried under a tree. Ballistics tests had shown that such a gun was among those that could have been used to carry out Richardson’s shooting.

Police are awaiting test results from the recovered gun to see if it matches bullet fragments from the shooting scene.