By Scott Glover and Joel Rubin(c) 2009, Los Angeles Times LOS ANGELES -- Michael Slider was home on a day off from his job as a police detective when his phone rang shortly after 10 a.m. It was his teenage niece. 'They shot Grandma. Someone shot Grandma,' she said over and over. Slider's mind raced. The girl had spent the night before with her grandmother, Pamela Lark, and Lark's daughter, Khristina Henry. For months, mother and daughter had been living in fear. Slider's stomach tightened with panic as he grabbed his keys. He sped down the freeway toward his sister-in-law's apartment, listening on his Los Angeles Police Department radio to police arriving at the scene. One asked for a supervisor, another for dispatchers to send 10 more patrol units. A third ordered someone to string up yellow crime tape. 'Jesus,' he thought to himself, 'this is bad.' By the time he arrived, Lark had been rushed to Cedars-Sinai Medical Center, where doctors pronounced her dead. 'I know who did this,' Slider told a lieutenant who tried to console him. 'His name is Tyquan Knox.' Four months earlier, in September 2006, Khristina had been robbed at gunpoint in a parking lot outside a bowling alley and had identified Knox as the gunman to police. Knox had been a promising but troubled football player from Crenshaw High School who had dreams of making it in the NFL. After the robbery, Knox's mother and others had contacted Khristina and Lark several times, proclaiming his innocence and trying to dissuade the teenager from testifying. Slider had urged Lark and Khristina to ask detectives for help in moving to the safety of another neighborhood. The detectives told Lark that money was available to help her relocate, but she had to find a new apartment before getting the funds. Lark had tried but failed to find a place. Now, she was dead, four days before Khristina was to testify against Knox. Police officers canvassed the neighborhood and found two women who had noticed a young woman sitting behind the wheel of a Chevy Impala about a block from Lark's apartment. The car, which still had temporary dealership license plates, had caught the women's attention because it was double-parked on the wrong side of the street. Minutes after the shooting, they saw a man dressed in black jog up the street and climb into the car. From the witnesses' description, detectives traced the car to a nearby dealership. A check of sales records turned up a handful of people who recently had bought Impalas. One was Knox. Police put the house Knox shared with his mother and stepfather under surveillance. Late that afternoon, Knox arrived with a friend and went inside. He was arrested as he tried to leave. A few miles away, about the same time, police arrested Keeairra Dashiell, Knox's girlfriend. Officers took her into custody as she tried to drive away from her family's home in an Impala with temporary dealer plates. Sitting in a cramped interrogation room, Dashiell, 18, gave homicide detectives a convoluted account of the morning: She had awoken early for a doctor's appointment. Tyquan had lent her the Impala and, as she left the house, an acquaintance who she knew only as Justin or by his gang moniker, Rampage, approached. He asked for a ride and she agreed. Dashiell told police she waited for Justin, never having asked what he was doing. It was still early, Dashiell said, and she fell asleep in the car. She awoke when Justin returned hours later. The homicide detectives sitting across from Dashiell were having none of it. They believed that Knox was the shooter and that Dashiell was covering for him. But Dashiell wouldn't budge. At one point, after Knox had been escorted into a nearby room, she yelled through the wall that she loved him and had said nothing to the police. 'They trying to say that you set it up. But I don't know what they're talking about, so don't let them lie,' she is heard saying on a department video reviewed by the Los Angeles Times. 'Girl, chill out,' Knox replied. Near dawn, more than 12 hours after her arrest, Dashiell's parents met with police. A detective laid out the situation: A woman was dead and their daughter's boyfriend was the prime suspect. Dashiell, the detective told them, essentially had placed herself behind the wheel of the getaway car but was refusing to give up Knox. 'She won't be the first woman that's serving life in prison as a getaway driver,' one detective said. 'What I'm hoping you guys will do is talk some sense into her.' (Begin optional trim) Dashiell graduated near the top of her class at Crenshaw and had earned a scholarship to the University of California, San Diego. Her parents saw Knox as a thug who someday would get their daughter in trouble and had pressured Dashiell to end the relationship. She had rebelled and briefly moved in with Knox and his family. Wearing a UC San Diego sweat shirt, Dashiell looked meekly at her parents as they were escorted into the interview room. 'I didn't do nothing,' she said. (End optional trim) Her mother, a bus driver, covered her face with her hands and began to cry. Her father, a railroad company worker, did the talking. 'I told you to stay away from Tyquan, but you didn't want to listen. Now look at your situation,' he said. 'We're looking at writing to you (in prison) for the rest of your life or until they stick a needle in your arm and kill you -- 'cause these people are talking about giving you the death penalty.' Her mother's crying turned to sobs. 'You need to tell these people the truth,' her father urged. 'These police are not playing.' Dashiell told police that Knox, in fact, had been with her in the car. Knox had picked her up and, when he told her to, she had climbed behind the wheel and waited. Dashiell told them more -- how she believed Knox was in line for a football scholarship and was worried that the robbery charge might derail his plans. She told them how Knox, days before the shooting, had sent her to the coffee shop where Khristina worked to get him a description to refresh his memory. Danette Meyers, the prosecutor in the case, speculates that Knox grew impatient waiting for Khristina to return from school and, when her mother appeared, decided 'to send a message one way or the other.' In June, after 2 1/2 years in jail, Dashiell accepted a long-discussed plea deal from Meyers. She pleaded guilty to voluntary manslaughter in exchange for a seven-year sentence and her testimony against Knox at his trial, which could begin this week. She will be the key to the prosecution's case, especially given that police never recovered the gun used to kill Lark and have no forensic evidence tying Knox to the murder. Although both are frightened, Khristina and her now-former boyfriend are planning to testify. (Begin optional trim) John Sweeney, Knox's attorney, said Knox is innocent of both the robbery and the slaying. He acknowledged that Knox was in the bowling alley parking lot the night of the robbery but said he was wrongly identified as the gunman. As for the murder, Sweeney said it would be a mistake to believe Dashiell -- despite her good grades and college scholarship. He pointed to police records that show a semi-automatic weapon was found in a bedroom in Dashiell's home the day she was arrested. Police attributed the gun -- a different style and caliber than the weapon used to kill Lark -- to Dashiell, but her lawyer said it was found in a sister's room. Sweeney also said that after her arrest, Dashiell was charged with assaulting a female guard in jail. 'She is not the angel she appears to be,' Sweeney said. Dashiell, Sweeney claimed, was obsessed with Knox and the idea of someday being married to a professional football player. She bought him gifts and tolerated his flings with other girls, according to Knox's parents. She tattooed his name on her wrist, they said. 'She was so madly in love with Tyquan that she would -- and did -- go to the lengths of setting up this killing,' Sweeney said. He maintained that the Justin figure is real and was enlisted by Dashiell. She changed her story, he suggested, only after being pressured by her parents and offered an incentive by prosecutors. 'They gave her a sweetheart deal that would entice her to say anything,' Sweeney said. (End optional trim) Slider, meanwhile, watched as his family threatened to pull apart at the seams following the killing. Lark's eldest daughter, a state prison guard, sank into a depression and battled insomnia. She was told she no longer could work as a guard and was forced to take a low-paying administrative assignment. Lark's grandchildren, who witnessed the killing, also have struggled. Her young grandson stopped talking, regressed on potty-training and developed a fixation with guns. Her teenage granddaughter started running with a rough crowd and stealing from family members. Khristina has managed better than others. She gave up for a time on the nursing classes she was taking when her mother was gunned down but recently has enrolled again and holds down a full-time job as well. She lives in her own apartment outside of Los Angeles. Slider said, 'What hit me hardest was what was happening to my family. I could not just sit back. Something had to be done.' Convinced that the detectives could have done more to protect Lark and Khristina, Slider did things he acknowledges he should not have done. He went into the department's computer system and printed out a copy of the detectives' case file, telling himself at first that it was 'just to have a record of what happened.' Slider gave the detectives' file to an attorney the family had hired for a lawsuit, hoping it might help to make a negligence case against the detectives. Police officials opened an investigation and found him guilty of misconduct. A disciplinary panel will hear the case in the coming months and decide if Slider's career is over. Recently, a judge tossed the family's lawsuit, saying the detectives acted appropriately and had no special obligation toward Lark because she was not the witness in the case. Meyers, the prosecutor in Knox's case, is reluctant to second-guess the detectives. She does not dispute, however, that more could have been done to protect Khristina and her mother. 'We hear about intimidation all the time,' she said. 'This was one where the police just didn't think anything would happen.' 