WAUWATOSA, Wis. (AP) -

Wisconsin authorities are looking into the death of a suburban Milwaukee police officer who was killed on duty.

Wauwatosa Lt. Gerald Witkowski says dispatchers unsuccessfully tried to reach Jennifer Lynn Sebena, 30, for a call about 3 a.m. Monday. He says officers started looking for her and found her dead with several gunshot wounds about 5 a.m. He didn't know if she inside or outside of her car.

Witkowski says the case is considered a homicide. Officers have no suspects.

Witkowski says Sebena enrolled in the police academy in January 2011 and began working solo in July. He says she was married and described her as a great person and officer.

Police are urging witnesses to come forward.

The state Justice Department's criminal investigation unit is helping in the investigation.