Child bride Wasila Tasi'u faces execution for rat poison "murder" of husband, 35 Facing death ... Sani Garba, 55, hold the picture of his 14-year-old daughter-in-law, accused of murdering her 35-year-old husband with rat poison. PROSECUTORS have opened their case against a 14-year-old girl accused of murdering her 35-year-old husband, with testimony from a child allegedly sent to buy the murder weapon: rat poison. Wasila Tasi'u, from a poor, rural family in the mainly Muslim north of Nigeria, could face the death penalty if convicted in a case that has outraged rights activists, who say a girl who married a man more than twice her age should be treated as a victim, not a criminal. Prosecutor Lamido Abba Soron-Dinki's first witness on Wednesday was a seven-year-old girl, identified as Hamziyya, who was living in the same house as Tasi'u and her husband Umar Sani, when the child bride allegedly laced his food with rat poison. Hamziyya was identified as the sister of Sani's "co-wife," referring to a woman the deceased farmer had married previously in a region where polygamy is widespread. Accused ... Many believe Wasila is the real victim. The seven-year-old testified that Tasi'u gave her 80 naira ($A.50) to buy rat poison from a local shop on April 5, the day Sani died. "She said rats were disturbing her in her room," Hamziyya told the court. The prosecution alleges that Tasi'u instead put the poison in the food she had prepared for a post-marriage celebration, perhaps because she regretted her decision to marry Sani. Judge Mohammed Yahaya, sitting at the Gezawa High Court, has entered a plea of not guilty for Tasi'u, who refused to respond at a previous hearing on October 30 when the charges were put to her. Tasi'u wept quietly at the hearing last month but appeared more composed in court on Wednesday.