Parolee Checked in Attack on Knott’s Kin : Crime: Teen-ager remains in critical condition at Escondido hospital after being bludgeoned last Tuesday.

The 17-year-old great-granddaughter of the Knott’s Berry Farm founder clung to life Thursday in a San Diego County hospital, while investigators questioned a prison parolee who lives in the semi-rural neighborhood of Fallbrook where Desire Anderson was bludgeoned early Tuesday.

“We’re looking at every possible motive,” San Diego County Sheriff’s Detective Al Collier said at a news conference held by the girl’s family. “Everything that looks like a possible lead, we will explore.”

Marion Knott, the girl’s grandmother, tearfully pleaded for anyone with information to come forward. The family on Wednesday offered a $10,000 reward, hoping to produce a break in the case.

“He, she, whatever, has to be found,” Knott said. “Whoever did this has to be mentally deranged. . . . I can’t think of who would hammer a girl’s head like that.”

An assailant apparently entered the family home in the 4400 block of La Canada through an unlocked sliding glass door to the mother’s bedroom, then walked into the girl’s bedroom, said Sheriff’s Lt. Doug Clements.

Although the unidentified parolee was interviewed, authorities said they still have no suspect in the case.

“We have not ruled out anybody,” Clements said.

The girl’s mother, Diane Anderson, told deputies she heard someone in her daughter’s bedroom who then fled when she called out to her daughter.

Desire, a Fallbrook High School honors student who wants to be a forensic doctor, underwent emergency surgery Thursday morning as physicians sought to reduce brain swelling caused by the attack. She remains listed in critical condition, said a spokeswoman at Palomar Memorial Hospital in Escondido.

The quiet neighborhood where the attack occurred sits in a small valley dotted with horse stables and avocado groves.

On a fence at the rear of the Anderson family’s four-acre ranch is a sign warning “No Trespassing Violators Will Be Executed.”

Jim Nash, a neighbor, said the attack has prompted him to let his dog sleep indoors for added protection.

“I just can’t wait until they catch whoever it is so I can relax,” said Nash.

About five miles north at Fallbrook High, students and faculty were still groping to understand the incident. Desire has been described by family, friends and acquaintances as mature, bright and pretty.

“Everybody I’ve talked to, they can’t think of anything in the world that would have caused this,” said Becky Kvikstad, a French teacher for whom Desire is a teaching assistant. “It doesn’t make sense.”