CARMEL, Ind. (WXIN) — An Indiana mother has been sentenced to 115 years in prison after being found guilty in an oatmeal-poisoning murder plot that stemmed from a contentious custody battle between her and the father of her 2-year-old child.

Heidi Littlefield, 42, was found guilty of murder and two counts of conspiracy to commit murder in August by a Hamilton County jury in the death of her ex-boyfriend, Francis Kelley.

Kelley was found dead on a couch in his Carmel home on Jan. 18, 2021.

According to court documents, Littlefield conspired with her daughter, Logan Runyon, in plotting the death of Kelley. Kelley and Littlefield shared a 2-year-old child together and had been in a custody battle when Littlefield began plotting Kelley’s murder.

Court documents reveal that between October 2020 and January 2021, Littlefield worked with Runyon to poison Kelley with fentanyl, in hopes of making his death look like an overdose.

Investigators spoke with Robert Walker of Englewood, Ohio — another accused conspirator in the plot — who told detectives that Littlefield put fentanyl in Kelley’s miso soup in October 2020. Walker also told police it was Littlefield’s idea to put the fentanyl in Kelley’s oatmeal, which he ate on January 15, 2021, the last day anyone heard from Kelley.

Court documents reveal a text conversation between Kelley and Littlefield that may have been his last.

“Did you do something to the oatmeal that was in my fridge?” Kelley texted Littlefield on Jan. 15, 2021, at 1:37 p.m.

“What the actual f— are you talking about???” Littlefield responded.

“You were in my fridge last night and it tasted funny after a couple bites and now I’m lightheaded,” Kelley responded at 1:41 p.m., adding he was having trouble focusing on work.

Kelley had been working from home that day. Court records show that the last email Kelley sent was at 1:56 p.m. Calls and messages to Kelley after 1:56 p.m. were marked unanswered and unread. Kelley’s employer said it was “highly unusual” for Kelley to go dark during this time frame since he was usually active until 5 p.m.

Littlefield continued to text Kelley after he asked her about the oatmeal. She accused him of being on drugs and berated him. In a message sent at 1:52 p.m., she said she was tired of him “telling false info about me.” This message went unread. So too did her message at 4:04 p.m. where Littlefield told him she had stopped by his house a little earlier with their daughter but her knocks at his door went unanswered.

Carmel police ended up making a welfare check at Kelley’s home two days later after a different ex-girlfriend became concerned when Kelley failed to pick up their 9-year-old child as previously scheduled. Police didn’t enter Kelley’s home nor did they make contact with Kelley on Jan. 17, however. It wasn’t until the following afternoon that Kelley was found when the same ex went to his home and discovered him dead on his couch.

Police were called to Kelley’s Howe Drive home where an inspection of Kelley’s body noted bruising found around his right eye, right elbow, knees and left hand. A small baggy was also found under the couch. It tested positive for cocaine but an autopsy later revealed fentanyl in Kelley’s system, not cocaine.

On Jan. 20, 2021, the coroner determined Kelley’s manner of death to be asphyxia due to manual strangulation. There was also blunt force trauma to his head.

When Walker was arrested on a warrant in Ohio in March 2021, he told detectives with the Carmel Police Department that he wanted to tell them about Kelley’s death and Littlefield and Runyon’s involvement.

Walker told police that Littlefield paid him $2,500 to hire someone to kill Kelley. Walker instead used the money on drugs, saying he had no intention to go through with his promise.

According to Walker, Littlefield talked about killing her “baby’s daddy” because “she would be failing her daughter if (Kelley) didn’t end up dead.”

Walker even implied Littlefield wanted Runyon to take the fall, asking her own daughter if she was “cool with going to prison for the rest of her life.”

Walker told investigators the details of Kelley’s death, saying it was Runyon who’d told him what happened in Kelley’s home in Carmel.

According to Walker’s interview, Littlefield poisoned Kelley’s oatmeal by adding fentanyl to the food. Then, she and Runyon pried open the window and snuck inside Kelley’s home where he was found unresponsive but still breathing. Littlefield then allegedly used Kelley’s “favorite tie” to strangle him while also smashing his head against the ground.

Runyon, who was sentenced to 26 years in prison for her part in the murder, testified against her mother as part of her plea deal. Runyon corroborated the events Walker described.

Littlefield maintains her innocence, according to the IndyStar, stating she intends to appeal the court’s decision. Two of Littlefield’s own children reportedly told the judge that society was better off, however, with Littlefield behind bars.

Court documents also reveal Littlefield’s boyfriend at the time of Kelley’s murder, who is also the father of the child Littlefield was pregnant with at the time of her arrest, recorded conversations between Littlefield and himself that he gave to police. In these conversations, Littlefield can be heard plotting to overdose Kelley on fentanyl and talking about how she wants Kelley dead.

Walker signed a plea deal for one count of conspiracy to commit murder, according to court records. He was sentenced to 10 years in prison.