(CBS4) - The Fort Collins woman accused of shooting and killing her ex-boyfriend and the father of her child was officially charged with first-degree murder in Boulder County Court on Tuesday. Devan Schreiner is accused in last Wednesday's shooting death of Jason Schaefer in Longmont.

Police believe Schreiner approached Schaefer on Oct. 13 while he was at a group of neighborhood mailboxes on Heatherhill Street by Renaissance Drive, shot him several times and then ran off. Schaefer died at the scene.

Both Schreiner and Schaefer had worked for the U.S. Postal Service in Longmont but Schreiner was fired about two weeks before the deadly shooting. The two share a child and police said that Schaefer was trying to change his parental custody agreement.

The judge on Tuesday also scheduled Schreiner's preliminary hearing for January.