A white Alabama police officer charged with murder in the shooting death of a black man will go before a judge at a March 24 preliminary hearing.

Authorities on Wednesday arrested 23-year-old Aaron Smith for the fatal shooting of 58-year-old Greg Gunn.

Gunn's family attorney says he was unarmed and walking home on Feb. 25 when Smith attempted an unlawful search. Gunn died in a neighbor's yard just steps away from his house.

Smith's attorney says the arrest is a "political witch hunt" meant to "quell public unrest." The attorney says Gunn resisted Smith and fled.

The Montgomery district attorney says investigators found probable cause for the charge but will not release additional information.

Gunn's family and friends have planned a "peaceful" march before his funeral on Saturday.