Police racing to find a Dallas-area rapist who appears to be preying on members of a national black sorority have released a written timeline of the attacks and additional details about a surveillance video.

Police say the video, which was previously released, is of a man who called one of the Plano victims from a convenience store payphone in Mesquite to inquire about her welfare after the April attack.

Plano police spokeswoman Heather Bowden says the victim doesn't know him; "we want to talk to this guy pretty bad." Detectives have a definite DNA profile of the suspect.

Police in Plano, Coppell and Corinth are investigating at least four sexual assaults, all involving black women in their mid-50s to mid-60s who are Delta Sigma Theta members.