Coppell police said they were unable to determine why 55-year-old Jayne Peters killed herself and her daughter, Corinne. But they believe she was still mourning her husband, who died of cancer in 2008, and was in serious financial trouble.

“We can’t pin down a motive. Only she will ever know,” city spokeswoman Sharon Logan said.

Police released documents from their completed investigation Thursday after an open records request from The Associated Press.

The bodies of the mayor and her daughter were found by police at their home after Jayne Peters did not show up to a July 13 City Council meeting.

According to police, Corinne Peters was seen for the last time on July 12 around 6 a.m. loading items into her car. About 30 minutes later, the mayor was seen unloading the items, police said. Police said that sometime in that 30-minute period, Jayne Peters shot her daughter in the laundry room.

They said it was hard to establish the exact time of death for the mayor but that she killed herself late that evening or in the early morning hours of July 13. She had taken a pillow, blanket and book about coping with suicide into the upstairs bathroom where she killed herself. Photos of her husband and daughter were inserted in the book.

At some point after killing her daughter, police say Jayne Peters placed a pillow and four stuffed animals outside the laundry room.

The police documents and crime scene photographs show Peters tried to get her affairs in order and make the grisly discovery easy on the authorities who came to her home. She left an envelope taped to the front door addressed to “First Responders” that contained a house key and an apology “for what you’re about to discover.”

She left several notes for investigators. One identified a computer and cellular phone as “City Blackberry and Computer.” Another contained instructions on how to take care of the family pets; one requested there be no funeral or memorial services.

A typed note found in the kitchen read: “My sweet, sweet Corinne had grown completely inconsolable. She had learned to hide her feelings from her friends. But the two of us were lost, alone and afraid. Corinne just kept on asking, ‘Why won’t God let me die?’ We hadn’t slept at all and neither one of us could stop crying when we were together.”

Jayne Peters was last seen around 12:30 p.m. on July 12 walking along a busy street after returning a rental car.

Peters, a contract software developer who had served on the City Council for a decade before being elected mayor in 2009, appeared to the outside world to be a well-to-do career woman who devoted much of her time to being an efficient mayor and mother.

That image was shattered after her death when it was revealed she was in deep financial distress and was under suspicion of using her city credit card for personal expenses. Her daughter had told friends she was headed to the University of Texas, but the school has since said the young woman never even applied.

Logan said the city attorney determined after Jayne Peters’ death that she had charged about $6,350 in personal expenses to her city credit card.

Coppell is a city of about 40,000, located 15 miles northwest of Dallas.