St. Martin Parish Sheriff's deputies on Wednesday arrested a woman accused of killing her brother’s pregnant girlfriend Tuesday night in Arnaudville.

Toni Trimble Thomas, 32, of Breaux Bridge, was booked on second-degree murder and second-degree feticide in the killing of 24-year-old Ashley Nichole Meche, who was eight months pregnant, said Maj. Ginny Higgins, a spokeswoman for the St. Martin Parish Sheriff’s Office.

Meche was found stabbed to death about 5:30 p.m. Tuesday in a residence in the 1100 block of Courtableau Highway, Higgins said. The baby did not survive the attack.

There were no further details on the attack or the weapon used in the stabbing, Higgins said.

Thomas’s motivation for the killing was not immediately known to deputies, but they are continuing to investigate, Higgins said.

Higgins said there were no immediate signs of Thomas having a violent or criminal past, but there was recently an incident with her disappearing.

“About a few weeks ago (Thomas) would disappear and they would be looking for her,” Higgins said.

Meche’s boyfriend, Mark Trimble, was seen leaving the home with his sister, Thomas, about 4:30 p.m. Tuesday. Investigators said Trimble was not present or involved in the homicide though he had been detained and questioned.

“Although they were both at the home at one point, (Trimble) left a few hours before it happened,” Higgins said.

Thomas, who was booked into St. Martin Parish Correctional Center, did not have

Update, Wednesday 5:10 p.m.

The sister of Ashley Nicole Meche's boyfriend was arrested Wednesday afternoon in the death of the eight-months pregnant woman, according to the St. Martin Parish Sheriff's Office.

Toni Trimble Thomas, 32, of Breaux Bridge, has been booked on one count of second-degree murder and one count of second-degree feticide.

Through the course of the investigation, it was determined that Meche's boyfriend, Mark Trimble, had no involvement in the homicide and was released from custody, St. Martin Sheriff's spokeswoman Maj. Ginny Higgins said in a news release.

Mark Trimble had been at the victim’s home earlier on Tuesday, the day she was killed; however, he was not present or involved in the homicide, Higgins said.

No motive for the homicide has been established, Higgins said.

Update, Wednesday 11:50 a.m.: The two suspects wanted for questioning in the homicide of a pregnant woman in Arnaudville are in law enforcement custody, said St. Martin Sheriff's spokeswoman Maj. Ginny Higgins. 

Mark Trimble has been identified as the boyfriend of Ashley Nicole Meche, the victim of Tuesday night's homicide. Toni Trimble Thomas has been identified as the sister of Mark Trimble.

The cause of Meche's death has been ruled a stabbing, Higgins said. 

Original story: The St. Martin Sheriff's Office is searching for two adults wanted for questioning in the slaying of a woman who was eight months pregnant, Sheriff's Office spokeswoman Maj. Ginny Higgins said. 

Mark Trimble, 29, and Toni Trimble, 32, both of Catahoula, are wanted for questioning in the killing of 24-year-old Ashley Nicole Meche in Arnaudville, Higgins said.  

Deputies found Meche dead about 5:30 p.m. Tuesday in a residence in the 1100 block of Courtableau Highway, Higgins said. The Trimbles were last seen leaving the residence at 4:30 p.m. Tuesday, before Meche was found dead. 

Higgins asked anyone with information on their whereabouts to contact the Sheriff's Office at (337) 394-3071.

Follow Grace Toohey on Twitter, @grace_2e.