Defense lawyers tried to get the sexual assault case against a former Norwalk police lieutenant dismissed in Stamford Superior Court Thursday. Thomas Cummings is accused of having sex with two underage boys and trying to lure a third into a sexual encounter. During the hearing, the defense said an investigator in the state's attorney's office had a conflict of interest because he used to be a Norwalk police officer and was once investigated by Cummings. The defense also called a witness who claimed he overheard another investigator in the state's attorney's office refer to Cummings with an anti-homosexual remark.