A police officer put his knee on the back of a Black pregnant woman in Kansas City, Missouri, during an arrest captured on video that led to daily protests outside City Hall.
The Sept. 30 arrest occurred during a confrontation between police and people gathered outside a gas station for a balloon release in memory a recent murder victim, said Stacy Shaw, a lawyer for Deja Stallings 25.
Officers were trying to break up the crowd and make an arrest when a woman, identified by Shaw as Stallings, began "hindering and interfering" with law enforcement, according to a statement by Kansas City police.
"Then she was handcuffed, turned to her side and immediately placed in a seated position," police said. "The officer who arrested the woman stated he took care not to apply pressure with his legs."
Video posted by Shaw appeared to show an officer placing his right knee on the face-down woman's back for at least 16 seconds during the arrest.
"Common sense and basic humanity" should have prevented Stallings from being tackled and arrested, Shaw told NBC News on Friday.
"I could never treat a pregnant person like that. Even if she had hindered arrest, there was no justification for her to be body slammed to the ground and the officer's knee to be forced into her back."
Stallings "was transported to an area hospital, where she was evaluated and released," according to police.
Local prosecutors confirmed on Friday they're looking into the matter.
"The allegation is that there was excessive use of force," said Michael Mansur, spokesman for the Jackson County Prosecutor's office. "We're reviewing that. So that means we've asked KCPD to open an investigation and we're asking for other information."
The Kansas City Police Department declined to identify the officer in the video because he has not been charged with any crimes.
"We have cooperated with the Jackson County Prosecutor's office and have turned over all video recordings," Kansas City police Capt. David Jackson said in a statement. "We have continued to review the incident for any policy or procedural violations."
Friday marked the eighth consecutive day of camped protests in front of City Hall.
Protesters are demanding action against the officer who arrested Stallings and the ouster of Chief Richard Smith, according to Shaw. Smith's department has been under fire for more than a year, following the fatal police shooting of Terrance Bridges, 30.
"There are no imminent plans to require the individuals outside of City Hall to vacate," said Morgan Said, a spokesman for Kansas City Mayor Quinton Lucas.
Stallings is due to give brith to a baby girl on Oct. 19.
"Mentally she's still very traumatized," Shaw said. "Physically, besides the high blood pressure, we don't know about any permanent damage right now."