TAMPA — Her stepfather lay dead under a blanket behind a locked bedroom door. Looming in an open window in her family's Carrollwood home, the 21-year-old college student waited through the night for her mother to come home.
She was alone. She had a gun.
Nicole Nachtman would later tell people she had second thoughts when Myriam Dienes finally arrived after 9 p.m. Thursday, detectives said. She decided to slip out a bedroom window. But her mother spotted her.
In the driveway, Dienes confronted her daughter. Why, she asked, wasn't she away at school?
Nachtman pulled the gun. She shot her mother three times. She ran.
That is the tale told in an arrest affidavit Hillsborough County sheriff's officials released Monday in the case against Nachtman. A sophomore at Florida State University, she is facing two counts of first-degree murder in the deaths of her mother, Myriam Dienes, and stepfather, Robert Dienes.
The arrest report notes statements from witnesses, including a man who said Nachtman told him "screaming voices" in her head moved her to commit the killings.
"What we were able to gather is that she confessed to other people," said sheriff's spokeswoman Cristal Bermudez Nunez. "When we ask her questions, she doesn't answer us."
Arrested Friday in Tallahassee, Nachtman returned Monday to Hillsborough County, where she was booked into the Orient Road Jail. She said nothing, keeping her head low as deputies led her into a booking room. She was held without bail.
The investigation began Thursday night after neighbors called 911 upon hearing gunshots near the home at 14110 Fennsbury Drive. When sheriff's deputies arrived about 9:30 p.m., they found Myriam Dienes lying in the driveway. She had been shot once in the neck and twice in the torso.
In the house, they later pried open a locked bedroom door to find the decaying body of Robert Dienes. He had been shot once in the neck.
After the killings, according to the report, Nachtman drove to FSU. When she arrived, according to the report, she told a woman that if anyone asked, she was to say that Nachtman was in her dorm room Thursday night.
Detectives called Nachtman's cellphone. She told them she had been at the school for a day or two, the report stated. But neighbors had reported seeing Nachtman peering out the windows of the home the night of her mother's shooting.
University officials said that Nachtman's student ID card had not been used in the previous seven days, according to the report. The card's first scan was recorded at 10:24 a.m. Friday.
A man, who was not identified in the report, told detectives that Nachtman told him she visited the FSU campus Tuesday to pay for her dorm room. While there, according to the report, she continuously heard "screaming voices in her head" and began to think about killing her mother.
"When she began seeing signs on campus inferring that your dreams were about to come true," the man told detectives, "she drove back to the Tampa Bay area and drove to the residence of the victims."
After killing Robert Dienes, the voices began to fade, the man told detectives. Nachtman began to think "she could do this," the report stated.
She waited overnight for her mother, Myriam Dienes to return home, the report said. She began to have second thoughts before Myriam Dienes finally arrived and caught her daughter sneaking out the window.
Myriam Dienes was a captain in the Naval Reserve and had just returned home from service the night she was killed, Hillsborough sheriff's officials said. Her family said she had just been promoted to captain this year. Robert Dienes worked for the government and in law enforcement before retiring. The couple had previously lived in Virginia.
Court records show Nachtman had been the subject of a lengthy custody dispute that began in 1998 between her mother and biological father, Ronald Nachtman. He made child support payments until 2013. He did not return calls Monday for comment.
Hillsborough sheriff's officials said they had no indication that Nicole Nachtman has a history of mental illness. She has no history of arrests in Florida.
She has been a student at FSU since 2013, school officials said. She was majoring in pre-international affairs. Before college, she attended Florida Air Academy, a military-style boarding school in Melbourne.
People who knew her there described a quiet and friendly girl who kept to herself and aspired to a military career.
Matt Watkins, who was friends with her at the school, said she was also a student who was ridiculed and harassed. Typically, Watkins said, Nachtman would avoid her school tormentors or just ignore them.
"She didn't seem to be the type that would be driven to such a violent act," Watkins said. "The only thing I can think is that she needed help prior to it, and she didn't get the help she needed and snapped."
Times news researcher John Martin, staff writer Zack Peterson and photographer Octavio Jones contributed to this report. Contact Dan Sullivan at firstname.lastname@example.org or (813) 226-3386. Follow @TimesDan.