COPPELL, Texas -- When police arrived at a suburban Dallas mayor's sprawling upscale home, they quickly realized something was very wrong. Rather than attend a City Council meeting, Mayor Jayne Peters had apparently taped an envelope to the door with a key and an ominous note inside.

Something unpleasant awaited them, warned the typed missive.

Inside the two-story brick house, Coppell police found a horrific scene Tuesday night. Peters and her 19-year-old college-bound daughter were both dead of gunshot wounds to the head, an apparent murder-suicide committed by the mayor, investigators say.

Three other notes were found at the house. But they did not offer an explanation for the deaths, only instructions for managing family affairs, such as care for the dogs, Coppell Deputy Police Chief Steve Thomas said Wednesday.

Bob Mahalik, mayor pro tem who is now acting mayor of the city, said he had a gut feeling something was wrong when the usually prompt mayor didn't show up for the meeting Tuesday night.

"But nowhere in your wildest dreams did you think it would be that far not right," he said.

Thomas said a semiautomatic handgun was used in the shootings, and there were no signs of a struggle.

A small collection of flowers, wreaths and cards decorated the front porch of the Peters' 3,850 square-foot brick home, where the mayor and her daughter, Corrine, lived alone. A printed letter said: "Please know that you are loved no matter what happens. I know that God is with you and giving you comfort. You both are with Don, a wonderful husband and father. A family again."

The mayor's husband, Donald Peters, died of cancer in 2008 at the age of 58.

Jayne Peters was a contract software developer who served as mayor of Coppell, a city of about 40,000 located 15 miles northwest of Dallas, for the past year. Her term was to expire in 2012. She had been a council member since 1998.

She attended Miami University in Ohio. In her official biography on the city's website, she said, "Coppell is a community with a huge heart, and we take care of one another."

"She enjoyed what she was doing as mayor and she was good at what she did," said Mahalik, who last saw Peters waving and passing out candy at the city's Independence Day parade. "She attended almost everything, every ribbon-cutting, speaking at the schools, the chamber, regional meetings."

Todd Storch, of Coppell, had known Peters for about a year. When his 13-year-old daughter died in a skiing accident in March, Peters was there for him and his family and later took a spot on the foundation he formed in his daughter's name to increase awareness for organ donation.

"She was just one of those rocks that was always there. We kind of grieved together," Storch said.

Corinne Peters graduated from Coppell High School this year. A classmate said she was bound for the University of Texas at Austin, and neighbors said the mother and daughter seemed happy.

A close friend, Ashley Johnson, said Corinne loved animals and was a phenomenal ballet dancer. There were no signs of serious strain between Corinne and her mother, Johnson said.

"Her and her mom fought sometimes, but it was like a normal teenager and mom relationship," Johnson said. "I never would have thought this would have happened."

Neighbor Diane Ianni said Corinne was excited about enrolling at Texas and frequently donned shirts with the university's longhorn logo and colors.

She said that when she recently saw Corinne, the teen was upset about having to miss at least two different summer orientation sessions at the Austin campus, the last time because her mom was having problems with her eye and had to go to a doctor's appointment. But she said Corinne recovered and had been back to her happy self.