Dynel Lane, accused of cutting a stranger’s unborn baby from her womb, appears in a Boulder District courtroom for her trial Wednesday, Feb. 17, 2016, in Boulder, Colo. Prosecutors charged Lane with attempted first-degree murder, assault and unlawful termination of a pregnancy in the March 2015 attack of Michelle Wilkins. (Matthew Jonas/The Daily Times Call via AP) NO SALES; MANDATORY CREDIT

BOULDER, Colo. (AP) — A woman accused of cutting an unborn baby from a stranger’s womb was obsessed with pregnancy, taking elaborate measures to convince friends and family she was expecting, a prosecutor said Wednesday as Dynel Lane’s trial got underway.

But a defense lawyer said Lane didn’t plan the attack and didn’t know what to do afterward.

Lane is charged with attempted first-degree murder, assault and unlawful termination of a pregnancy in the gruesome attack on Michelle Wilkins in March 2015.

Wilkins, who was 8 months pregnant, survived the attack, but her unborn baby did not.

In his opening statements, District Attorney Stan Garnett said Lane wasn’t pregnant but posted online photos of herself with a distended belly and claimed for more than a year that she was having a boy.

Lane’s friends even threw her a baby shower, Garnett said.

Wilkins, now 26, went to Lane’s home in Longmont on March 18 in response to an ad on Craigslist for maternity clothes.

Prosecutors say Lane hit Wilkins with a lamp, cut her with a broken piece of glass and removed the baby using two kitchen knives.

When Lane’s partner came home early from work to meet her for a prenatal appointment, he found the infant in a bathtub, according to police. He drove them both to a hospital, where Lane, holding the still-wrapped baby, told staff she had suffered a miscarriage.

Police said she then admitted the child wasn’t hers.

Defense attorney Jennifer Beck said in her opening statements that evidence shows Lane didn’t plan the attack and never intended to kill Wilkins.

The women chatted about motherhood, their partners, pregnancies and other things for more than an hour before the chaotic and frantic attack, Beck said.

Lane wore a gray pantsuit and a blue button-down shirt in court Wednesday and wasn’t handcuffed.

The case roiled anti-abortion groups because Lane wasn’t charged with murder. Garnett said he couldn’t file a murder charge because a coroner found no evidence the fetus lived outside the womb.

That prompted Colorado Republicans to introduce legislation that would have allowed prosecutors to file murder charges for killing a fetus, but Democrats rejected it. It was the third time such a proposal failed in Colorado, setting it apart from 38 states that have made the killing of a fetus a homicide.

The charge of unlawful termination of a pregnancy that Lane faces is the result of a new law intended to be a compromise between opponents and supporters of abortion rights. The maximum punishment is 32 years in prison.