the prosecution claimed ali irsan was some sort of a son-in-law serial killer. >> nesreen told me thatelp and at the irsan's home, in montgomery, texas. did that ended up getting prosecuted? >> it did not. >> why? >> because he claimed it was self defense, and it was treated as such. >> -- that it was self-defense. >> then detective of the montgomery county sheriff's office reinvestigate that 1999 killing for the pass days in the task force. he said it started when the eldest daughter wanted to marry a man he disapproved of. in response, she says, irsan locked her in her room and beat her daily. >> and asked her frequently during the beatings, do you still love him? >> but the couple was persistent. and eventually married. just three weeks later, that new husband was dead in the irsan home. and this scene look like self-defense. the son-in-law had a gun in his hands. and ali irsan said he shot him to protect himself and his family. >> prior to the murder itself, ali irsan had filed reports with the sheriff's department that the victim was harassing the family, threatening the family. >