(CNN) -- A teenager has been formally charged in the killings of her mother and two young brothers, a crime that has left the family's tiny Texas town of Alba reeling.

Police are not releasing the daughter's name because she is a juvenile, but said they believe she was angry because her parents would not let her date one of three other suspects.

Authorities say the girl took part in the slayings, The Associated Press is reporting.

She was found hiding in a mobile home where one of the suspects lived, said Rains Sheriff David Traylor.

Also arraigned on three counts each of capital murder are: Charlie James Wilkinson, 19; Charles Allen Waid, 20; and Bobbi Gale Johnson, 18, who is female.

Bond was set at $1.5 million for each of the four, said Traylor.

Traylor said the teenage daughter had been dating Wilkinson.

"Early on in the investigation it was revealed that the juvenile and one of the suspects were dating and made to break up," Traylor said in a statement. Watch investigators sift through remains of burned home »

The Caffey family was sleeping when the pre-dawn attack on Saturday began, he said.

According to Traylor, the mother, Penny Caffey, 37, was shot and stabbed. Tyler Caffey, 8, was stabbed. Mathew Caffey, 13, was shot and stabbed. Authorities said they found the family in the ashes of their home, which had been set on fire.

The teenage girl's father, Terry Caffey, was shot in the head but was able to crawl 300 yards to a neighbor's home where 911 was called. Caffey helped police identify one of the suspects, said Traylor.

The sheriff told reporters late Sunday that Terry Caffey was on his way to surgery to have four slugs removed.

Carl Johnson, a family friend, told the AP he saw the bloody trail the father left as he dragged himself to a neighbor's house.

Johnson told AP the family members were musicians and that the boys played guitar and harmonica and the mother is a church piano player.

"I just thought the whole world of the family," said Johnson, 75. "They were good Christian people. [The father] was like a son of my own."

The killings shocked many in the small east Texas town, the town's mayor said Sunday.

"There hasn't been a murder here in 18 years," said Orvin Carroll, longtime mayor of Alba -- a town of about 430 people east of Dallas.

"We are all just a little shocked. This is a place where people do not lock their doors. But that is changing," Carroll added.

"We can't believe this could happen to a mother and her children. Not here." E-mail to a friend

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