Four women from an escort service have been charged with killing a Missouri man who stopped to help them when their car got a flat tire, according to reports.

Deputies say Ralph Cross, 55, of Wilson City, wound up paying for his act of kindness Tuesday with a bullet to the back.

Brittany Curry, 28, Ponesha Taylor, 23, Johniesha Simmons, 19, and Lauteshia Dotson, 23, all of Memphis, Tenn., were arrested Thursday on charges of first-degree murder, armed criminal action and unlawful use of a weapon, Fox 13 Memphis reports.

The women were in Missouri after advertising escort services online, KFVS-TV reported.

They were stuck with a flat tire Monday night when Cross stopped and offered to help, the station reported.

Investigators believe Cross bought them a new tire and then invited them back to his house where they spent the night.

A person who was in the house told deputies that Tuesday morning he saw Cross arguing with three of the women while a fourth sat in a white car, the Sikeston Standard Democrat reported.

The person said that as he was walking down the street he heard a noise and saw the three women rush out of the house and jump into the car, the paper reported.

Acting Mississippi County Sheriff Branden Caid told the paper that over the next two days investigators obtained surveillance video from local businesses showing the four women with Cross before he was shot.

Memphis TV stations aired images taken from the video which generated tips and led to the women being identified.

Caid told the paper that family and friends of the women then persuaded them to return to Missouri and answer questions.

During the questioning, Simmons and Dotson told investigators that Curry shot and killed Cross in front of Taylor, KFVS reported.