The killing of African-Americans by U.S. police officers is reminiscent of the lynchings the black community faced decades ago, argues a professor of constitutional law.

There is "a very clear connection for many people in the African-American community between the Jim Crow era — the lynchings that took place there — and the murders by police today," Gloria Browne-Marshall, a professor at John Jay College in New York City, told The Current's guest host Duncan McCue.

"When you can't get an indictment in the 21st century — when it's on video that someone just shot another person in the back and that person who's the shooter happens to be in law enforcement — then there is a clear connection between what happened then and what's going on now."

Browne-Marshall was discussing the news that the U.S. Justice Department has reopened the case of Emmett Till, a black teenager kidnapped, beaten and murdered in Mississippi in 1955.

Till was a 14-year-old Chicago boy visiting family in the south when a white woman, Carolyn Bryant, accused him of whistling at her and making advances. After the brutal assault, his body was dumped in the Tallahatchie River. Two men arrested and charged in his death were acquitted by an all-white jury, but the boy's death was a catalyst for the civil rights movement in the U.S.

"[Unless] we look at this as Americans ... Emmett Till is always going to haunt us," Browne-Marshall said.

Last week, the U.S. Justice Department reopened the case, citing "new information," but Browne-Marshall argued that it could be a political ploy to make Attorney General Jeff Sessions "seem like he's somewhat attuned to these issues."

"I think it's necessary for us to really look at what the motivation is," she said.

"Is this something just to take our eyes away from the Mueller investigation, the Russian conspiracy and everything else that's going on in this country by going back to 1955's murder case?"

She said that she hoped "we can start talking about not just what happened in 1955, but what's continuing to happen today."

What connects the killing of Till and the police-involved deaths of black people today — such as the death of Eric Garner in 2014 — is the way "society has accepted the cold-blooded murder of African-Americans and allowed it to just be a part of life," Browne-Marshall told McCue.

American society needs to examine whether it is excusing those deaths "because it's happening to people of colour."

"We can't go forward, we can't heal when we continue to use certain people as a rationale for their own demise — like it's supposed to happen that way, they brought it on themselves," she said.

"This country, if it's not going to face it, then we're going to be looking 50 years from now and say Eric Garner in the same way we said Emmett Till."