SPRINGFIELD, Mo. (AP) — A man accused of 2017 killing of a transgender teen whose body was set on fire in southwest Missouri told law enforcement officers that he tried to make the death quick and painless, a prosecutor said in an opening statement Monday.

Andrew Vrba, 21, is charged with first-degree murder, armed criminal action and abandonment of a corpse in the killing of 17-year-old Ally Steinfeld. Three others have pleaded guilty for their roles in the death.

Neither side disputed in their opening remarks at a bench trial that began Monday that Vrba killed Steinfeld, the Springfield News-leader reported. The prosecution contends the killing was premeditated, while the defense countered that it was not premeditated.

Vrba had been missing for weeks when her burned remains were found in September 2017 in the town of Cabool, a rural area about 70 miles (115 kilometers) east of Springfield, Missouri. Authorities say the crime wasn’t motivated by Steinfeld’s gender identity.

Texas County Prosecutor Parke Stevens said that the evidence will show that Vrba planned to kill Steinfeld, and that he later disposed of the body by burning and crushing the remains.

Stevens said in his opening remarks that Vrba told officers that Steinfeld died in his arms. He also told them that he first tried to poison Steinfeld, who wouldn’t drink the poison.

“The defendant deliberated and reflected and acted upon his intuition to kill (Steinfeld), whether it be his first attempt by poisoning or his second by stabbing,” Stevens said.

But defense attorney Tom Jacquinot said in his opening statement that the evidence will show Vrba did not premeditate to kill Steinfeld, who was his friend.

“He made a mistake and regrets it. He can’t take it back,” said Jacquinot, an attorney with the Missouri Public Defenders Office in Kansas City

Vrba was “confronting an extreme situation out of the blue,” his defense attorney said.

At the time of the killing, Vrba and Steinfeld were alone in the mobile home of Briana Calderas.

Steinfeld had been in a relationship with Calderas. Vrba was in a relationship with Calderas’ cousin, Isis Schauer, who was pregnant with Vrba’s baby.

The defense attorney said “what flipped the switch” was when Steinfeld — whom he described as angry and drunk — told Vrba, “I could just gut punch (Schauer) and kill that bastard child.”

Vrba “took it literally,” Jacquinot said, adding Vrba believed that if he didn’t take action Steinfeld would harm Schauer and his unborn baby.

“That interpretation is wrong,” Jacquinot said. “But it’s not premeditation.”

The trial is expected to last the rest of the week.

Vrba originally faced the death penalty, but the prosecutor said that’s now off the table based in part on the wishes of the victim’s family.