TAMPA, Fla. — Is she a calculated killer or mentally ill.

Testimony continued Thursday in the trial of a former Florida State University student accused of killing her parents in 2015.

A neighbor who heard the gunshots and the first responding deputy testified today.

Nicole Nachtman, 25, is accused of shooting and killing her mom and stepdad, Myriam and Robert Dienes, at their Carrollwood home four years ago.

Nachtman allegedly traveled from FSU to their Carrollwood home in August 2015. She allegedly shot and killed her stepfather, and hid his body in the house. According to the prosecution, Nachtman then waited for her mom to return from a work trip to murder her.

In testimony Thursday, neighbor Wesley Roe said he heard shots on the night of August 20, 2015. He said he saw a shadowy figure go away from the house towards a nearby lake.

Roe said he called 911 but hung up the first time because dispatchers took too long to answer. He said he called a second time and spoke to authorities. Both calls were played in court.

Hillsborough Sheriff's Detective Michael Pecylak was the first law enforcement official to arrive on scene. He testified that he saw Myriam’s body in the driveway of her home. He went door to door looking for witnesses. He described the scene as "eerie."

Lt. Robert Carr testified next. He went inside the Dienes’ home and found Robert Dienes’ body wrapped in a blanket. He said he noticed Dienes big toe sticking out.

Prosecutors says Nachtman killed Robert Dienes first and then waited for her mom to come home and murdered her — all because they were too strict and demanding. The Assistant State Attorney told the jury that Nachtman confessed everything to her brother after the murders.

Hillsborough County Public Defender Julianne Holt is leading Nachtman's defense.

She said Nachtman suffers from Schizophrenia and should be found not guilty by reason of insanity.

"Nicole Nachtman's life and her experiences and the things that she went through led her to develop a mental illness," Holt said. "A mental illness that is real and that exists."

According to the defense, Nachtman's relationship with her domineering mom led to a psychotic breakdown.

The trial is expected to last two weeks.  Nachtman faces life in prison if convicted.