( CNN ) -- A Florida police department is investigating one of its officers after he shot a 61-year-old woman in the back with a Taser on Tuesday afternoon . The incident was captured on videotape by a nearby witness . Officer Terry Mahan of the Tallahassee Police Department and other officers responded to complaints about open-air drug sales in the area , the police department said in a statement Wednesday . Probable-cause affidavits paint a scene in which officers feared for their safety because of angry residents berating police and calling others to the scene . Police had detained three people when Viola Young `` approached the police car inquiring about one of the individuals arrested , '' the statement said . `` An officer advised her to stay back , and a second officer approached Young and attempted to place her under arrest . '' In the video , Young can be seen yanking her arm out of Mahan 's grasp before turning and walking in the opposite direction . She takes only a few steps before the officer fires a Taser cartridge into Young 's back . The woman collapses face-down on the pavement , then rolls over onto her back . Another police officer approaches Young and arrests her . In a narrative included in a probable-cause affidavit , Mahan wrote that he went to the scene after officers there called for backup . When he got there , he saw two officers engaged with two suspects on the ground , and `` there was a crowd of people that had gathered around them and were yelling at the officers , '' he wrote . As Mahan put one arrested suspect in the back of a patrol car , Young pulled up , forcing Mahan `` to take [ his ] focus off of one of the arrestees and engage her , '' Mahan said in his report . `` Young 's actions obstructed officers while in the course of completing their legal duties , '' he wrote . Mahan told Young to leave . She responded that she wanted to know what was going , but Mahan told her , `` now was not the time for that , '' and instructed her to leave again . She refused , he wrote . `` I informed Viola Young that she was under arrest and reached out and took her left arm . Young yanked away , turned and began to move away from me in an attempt to defeat her lawful arrest , '' Mahan wrote . `` I deployed my Taser , and fired one cartridge striking Young in the back . Young was incapacitated and fell to the ground . '' Mahan took Young into custody `` without any further resistance , '' he wrote in his report . Texas student tased by police exits coma , enters rehabilitation . From another officer 's narrative , it appears police had to leave soon after the arrests `` due to the hostility of the individuals remaining at the scene . '' Young was medically cleared by Leon County Emergency Medical Services before being sent to the Leon County Jail , along with the other three individuals arrested , police said . None of the four faces drug-related charges . They all were charged with resisting an officer without violence , and Laguna Young was charged with a probation violation that Leon County Jail records indicate stems from a previous conviction on cocaine and drug paraphernalia charges . Family wants answers in Florida teen 's death after Tasering . Laguna Young was the only one of the four who had not been released as of Wednesday afternoon . It 's not clear if Laguna Young , 41 , is related to Viola Young . After reviewing the video of the tasing incident , Tallahassee Police Chief Michael DeLeo called for an internal investigation , he said . `` We will conduct a thorough investigation into this incident . We want to be transparent with the community by sharing what we can at this point , including the video , '' DeLeo said in a statement . Mahan has been placed on administrative leave with pay while the investigation is being conducted , DeLeo said . Because the case is now part of an internal affairs investigation , `` this will preclude us from making any other statements , other than what is in our release , in regards to this case until the full investigation is complete , '' police spokesman Officer David Northway said . Using a Taser on an 8-year-old ? Mom sues police , city .
Incident began when police responded to complaints of open-air drug sales in area . 3 people had been arrested when Viola Young arrived asking questions , police say . Video shows Young pull arm away from officer , walk off before he Tases her in the back . Police said she was not resisting arrest and that they were called because there is a large crowd at the scene.