The lawyers for a female Pennsylvania police officer charged with criminal homicide last month are trying to keep a video of her fatally shooting an unarmed motorist in the back out of the courtroom. Footage of Hummelstown police Officer Lisa Mearkle shooting two bullets into David Kassick's back as he lay face down on February 2 that was recorded by her stun gun has not been made public. Her attorneys asked a judge on Friday to bar the distinct attorney from releasing the video. Scroll down for video . Pennslyvania police Officer Lisa Mearkle is charged with criminal homicide in the shooting of David Kassick . Kassick, 59, was shot in the back while he lay face down on the ground on February 2. He was unarmed . Mearkle, 36, claimed she shot Kassick in self-defense because she saw him reach into his jacket for a weapon . A preliminary hearing to determine if there is enough evidence to send the case to trial is scheduled for Monday, CBS News reported. A lawyer working for Kassick's family who has seen the video, Christopher Slusser, said it 'leaves nothing to the imagination'. Mearkle is free on bail and suspended without pay . He said: 'Whether she would have been charged or not had the video not existed, I can't answer that,' 'But I can tell you having that video, for me - I won't speak for the DA - but it made it very clear the DA had very little choice not to charge her.' Mearkle, who is free on bail but is under electronic monitoring, is suspended without pay. Dauphin County District Attorney Ed Marsico previously called the video the strongest evidence in the case when Mearkle was charged at the end of March. The stun gun's camera started recording when Mearkle, 36, used it on Kassick, 59, after she tried to pull him over for expired inspection and emissions stickers. Kassick sped away but she caught up to him after he got out and ran. Marsico said Kassick was trying to remove stun gun probes from his back when he was shot. Mearkle's lawyer, Brian Perry, said his client fired at Kassick in self-defense because she thought he was reaching for a gun. She performed CPR after the shooting. Kassick's family said he had struggles with drug addition but that he was not a violent person. A syringe was found near Kassick's body and he had alcohol and unspecified drugs in his system when he died. He was a construction worker. Dauphin County District Attorney Ed Mrisco (left) called video of the shooting the best evidence in the case . The offense of criminal homicide encompasses charges from misdemeanor involuntary manslaughter to murder . According to the arrest affidavit: 'At the time Officer Mearkle fires both rounds from her pistol, the video clearly depicts Kassick lying on the snow-covered lawn with his face toward the ground. 'Furthermore, at the time the rounds are fired nothing can be seen in either of Kassick's hands, nor does he point or direct anything toward Officer Mearkle.' Marsico planned to show the video on Monday, but Mearkle may waive the hearing. The motion filed by her defense team about the video is scheduled to be addressed on Tuesday. The offense of criminal homicide encompasses a range of charges, from misdemeanor involuntary manslaughter to felony first-degree murder. Prosecutors often narrow the charge later in the process, about the time when defendants are formally arraigned.
Pennsylvania police officer Lisa Mearkle charged with criminal homicide.
Stun gun took video of her fatally shooting David Kassick, 59, in the back.
Mearkle, 36, has claimed to authorities the shooting was act of self-defense.
Her attorneys filed motion to prevent DA from showing clip during hearing.
Lawyer for Kassick's family said video 'leaves nothing to the imagination.