( CNN ) The emissions sticker on David Kassick 's car was expired . That 's what first caught the attention of Lisa Mearkle , a police officer in Hummelstown Borough , Pennsylvania , who ordered Kassick , 59 , to pull over on February 2 . Instead , Kassick fled . Moments later , he lay dead on the ground in a yard near a relative 's home . On Tuesday , Mearkle was arrested on a homicide charge following a state police investigation into the shooting . Mearkle 's attorney , who described the use of deadly force in the case as justified , said he is girding his client for national scrutiny as the case finds itself on a growing list of officer-involved shootings . The final moments leading to Kassick 's death were captured on video which Dauphin County District Attorney Ed Marsico Jr. said was critical in bringing the homicide charges . It was around 4 p.m. on February 2 when the 15-year police veteran first attempted to pull Kassick over , according to the charging documents . Instead of pulling over , Kassick took off and Mearkle gave chase , flipping on her lights and sirens . Less than a mile away , Kassick pulled into the driveway of a relative he 'd been staying with and ran off on foot into the backyard , with Mearkle following close behind . As they ran through the yards behind Grandview Drive , the charging documents said , Mearkle fired her stun gun , automatically engaging a built-in audio and visual recording device . Marsico described the video : . `` She 's running , she 's tasing him , he falls to the ground . He 's sort of writhing around on the ground a little bit , '' Marsico said . Standing several feet behind his prone body , Mearkle shouts for Kassick to show his hands . Despite the commands , Marsico said there were multiple points in the videos where Kassick is seen reaching beneath himself , his hands obscured to Mearkle . Holding the Taser in her left hand , court documents said , Mearkle drew her gun in her right hand and , while continuing to shout `` show me your hands , '' fired twice into Kassick 's back . Kassick was pronounced dead at the scene . He was unarmed . Marsico said the video was critical in determining the first criminal charges brought against a police officer in a shooting like this in his 15 years as district attorney . `` He was face down on the ground , no weapon had been displayed . He did n't approach her , he did n't come toward her , he did n't verbally threaten her in any way , '' Marsico said of Kassick . `` It 's our position that her use of deadly force was not necessary . '' CNN has filed a Freedom of Information Act request to obtain the video , which it has not independently viewed . Mearkle later told investigators she thought Kassick had been reaching into his jacket for a gun , according to court documents . `` What was she supposed to do ? '' Mearkle 's attorney , Brian Perry said . `` She felt that this was the only option that she had . '' `` Keep in mind she had tased this individual four times and was screaming commands to him and he kept reaching under , '' Perry said . Mearkle was placed on electronic monitoring on Tuesday after posting $ 250,000 bail . `` This was an extremely difficult case for all involved but in the end , we are servants of Justice and must now allow the judicial process to conduct a fair and impartial review of the allegations that have been presented , '' the Borough of Hummelstown said in a statement . Hummelstown Borough announced on Wednesday that Mearkle had been suspended from the Police Department without pay .
Police Officer David Kassick faces homicide charge for shooting an unarmed man . Lisa Mearkle , 59 , was shot and killed after fleeing a traffic stop .