MIDWEST CITY, Oklahoma - New details have emerged in the alleged murder-for-hire of pregnant Midwest City mom Jessica McPherson-Brown.

Friday, Laquan Ashley became the fourth person charged with first-degree murder in the case. Investigators tied Ashley to the alleged gunman, Brodric Glover, who admitted to shooting McPherson-Brown twice after he was hired by McPherson-Brown's estranged husband, Fabion Brown.

Ashley's picture first showed up during the murder investigation when police released surveillance photos from the Belle Isle Wal-Mart. He was named then as a person who might have information regarding the killing. A newly released probable-cause affidavit connects Ashley to Glover on the night of the murder.

Ashley was caught on a series of surveillance cameras in the Midwest City and Oklahoma City area the night McPherson-Brown was killed. He had previously told police he was not in the Midwest City area, but in court documents investigators cited "surveillance footage from several locations and witness' testimony contradicts Laquan Ashley's statements during the first interview."

The surveillance footage shows Ashley, Glover and another woman together in a rental car. Investigators allege that car was used to drive Glover near the scene of the murder and get away from it.

Presented with the evidence, Ashley changed his story. The affidavit shows he admitted "he drove the car the night of the homicide, but did not know what Glover was going to do."

Glover told investigators that the two others with him were not aware of the murder and said they only knew they were "hitting a lick," which is a street term for committing a crime. Investigators believe Glover was lying to cover for Ashley and the other person in the car.

The court documents also show investigators listened in on several phone conversations, which may be evidence against Brown, who allegedly hired Glover to commit the murder. Those recorded conversations made by Brown "reveal that he knew additional information about the homicide investigation that could not be known by anyone except the killer or those who helped plan the homicide."

Brown has denied his involvement to News 9's cameras. He was previously charged with first-degree murder.

Brown's girlfriend, Emily Matheson, admitted to investigators that the rental car Ashley and Glover were in was used to drive to Midwest City to "carry out the murder of Jessica Brown."