MEMPHIS, Tenn. -- Memphis police officer Preston Hemphill, a sixth officer involved in the Tyre Nichols traffic stop, has been relieved of duty during an ongoing investigation, according to Memphis police.
Another officer, who has not been publicly identified, was also relieved of their duty and is being investigated, Memphis PD said Monday.
Later Monday evening, the Memphis Fire Department announced it fired two EMTs who responded to the scene for failing to properly assess Nichols as he lay beaten on the ground. A Memphis FD lieutenant was also fired, the agency said.
Hemphill deployed his Taser during the confrontation. In his own body camera video, Hemphill is seen chasing Nichols down the road, but then turns back to the scene of the initial traffic stop.
Hemphill was heard on his body camera video saying twice, "I hope they stomp his a--."
MORE: Memphis police release video of Tyre Nichols traffic stop
Hemphill, who is white, has not been fired or charged. Hemphill "was relieved when the other officers were relieved," a Memphis police spokesperson said.
Five officers, who are all Black, were fired and charged with second-degree murder in connection with Nichols' beating at a Jan. 7 traffic stop. Nichols, 29, died three days later.
Hemphill's attorney, Lee Gerald, said earlier that Hemphill was the third officer at Nichols' initial traffic stop. The first body camera footage released Friday was from Hemphill's device
"As per departmental regulations Officer Hemphill activated his bodycam," Gerald said earlier in a statement. "He was never present at the second scene. He is cooperating with officials in this investigation."
WATCH: Tyre Nichols' mom describes hearing son cry out for her
Nichols' stepfather, Rodney Wells, told ABC News Live on Friday night that he thinks "everyone [who] was active in the whole scene ... should be charged."
Attorneys for Nichols' family, Ben Crump and Antonio Romanucci, said they were extremely disappointed that Hemphill was relieved of duty but not fired or charged. The lawyers are also questioning why the Memphis police did not immediately announce Hemphill's name or that he was relieved of duty.
"Why is his identity and the role he played in Tyre's death just now coming to light?" they said in a statement. "We have asked from the beginning that the Memphis Police Department be transparent with the family and the community -- this news seems to indicate that they haven't risen to the occasion. It certainly begs the question why the white officer involved in this brutal attack was shielded and protected from the public eye, and to date, from sufficient discipline and accountability. The Memphis Police Department owes us all answers."
Shelby County District Attorney Steve Mulroy said in a statement Monday that the investigation was ongoing and more charges could be filed.
"We are looking at all individuals involved in the events leading up to, during, and after the beating of Tyre Nichols," the district attorney's office said. "This includes the officer present at the initial encounter who has not -- so far -- been charged, Memphis Fire Department personnel, and persons who participated in preparing documentation of the incident afterward."
"The DA's Office worked extraordinarily swiftly but thoroughly to charge those whose offenses were plain and clear and directly contributed to the death of Mr. Nichols, but in no way is this investigation over," the office added.
Hemphill was hired by the department in 2018.
ABC News' Whitney Lloyd contributed to this report.
SEE ALSO: Officials push for Tyre's Law in wake of fatal police beating