Opening statements started Wednesday in State Supreme Court in Brooklyn for a former NYPD sergeant who?s accused of killing his estranged girlfriend over child support payments.

Martin Peters, 41, is charged with murder, assault, intimidating a witness and other charges. Peters allegedly killed Juliet Alexander, the mother of his two children, in January 2001. Authorities claim he told Alexander he was going to stop making child support payments, hit her and then shot Alexander when she tried to flee her apartment at 365 Pulaski St.

Peters also allegedly shot family friend Nigel Calendar, who came by the apartment and witnessed the crime. Prosecutors say Peters threatened to kill Calendar if he told. Calendar is expected to testify against his friend. The defense says his story is false.