Surveillance images released in killing of Indiana pastor's wife

Indianapolis police released surveillance images Monday that show the man they believe killed a pregnant pastor's wife during a home invasion last week.

The two black-and-white still images were taken by a neighbor's security camera and show the suspect from behind with a hoodie pulled over his head.

Earlier in the week, police described the man that they believe shot 28-year-old Amanda Blackburn as a black male who is 5-foot-4 to 5-foot-9, with medium to light brown complexion and a slim to medium build.

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Blackburn was shot once in the head on Tuesday morning after her husband, Davey Blackburn, left for the gym shortly at 6:10 a.m. Witnesses told police that they heard gunfire a half-hour later, and a dark-colored SUV was seen speeding away from the scene, though it's unclear if the vehicle is connected to the killing.

During a news conference Friday, police said that more than one person may have been involved in the crime. There were no signs of forced entry, and the couple's toddler was found unharmed in a crib.

See photos of the Blackburns and their child:

In a statement released by his church last week, Davey Blackburn said that when he returned home from the gym, he found his wife dead. He has been "ruled out completely" as a person of interest in the case, Indianapolis Police told NBC News last week.

During the news conference, Indianapolis Police Capt. Craig Converse described the killing as a crime of opportunity.

"We believe that the people saw this as a home where they could get in and take some things. It just so happens that Amanda was home ... and she was murdered," Converse said.

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