A judge in Argentina has blocked the marriage between a 22-year-old woman and the man convicted of killing her twin sister in 2010.
Edith Casas insists Victor Cingolani did not murder her sister a model with whom he also had a relationship.
Cingolani was convicted of Johana Casas' murder and is serving 13 years in prison in the town of Pico Truncado.
The mother of the identical twins, Marcelina Orellana, says Edith Casas is "psychologically ill".
She filed a request for the wedding to be suspended.
Edith "is not in full control of her mental faculties and her physical and psychological well-being are in danger", said the mother's lawyer, Fabian Farias.
Relatives says Edith Casas has changed in the last 10 days, leaving home to live with Cingolani's sister and announcing the wedding.
"She was living with her parents before that and no-one could have foreseen such an abrupt change in her behaviour," Mr Farias told the Clarin newspaper.
The couple had planned to wed on Friday at the prison in the southern province of Santa Cruz, to avoid media attention.
But the judge suspended the wedding, adding that he would make a final decision by 31 December on whether Cingolani and Ms Casas can marry.
Mysterious death
Cingolani told Argentine media that his relationship with Johana was "casual" but that he was "in love" with Edith.
Edith maintains that Cingolani was unjustly convicted, saying he is "a guy who would not hurt a fly".
The exact circumstances of 19-year-old Johana Casas' murder, in July 2010, remain a mystery.
The model's body was found with two bullet wounds in a field.
A second man, Marco Diaz, Johana's boyfriend at the time of her murder, is awaiting trial charged with her murder.
- BBC
