U.S. Rep. John Yarmuth says the shooting at a Louisville Kroger that claimed the lives of two African Americans this week is a hate crime.

Maurice Stallard, 69, and Vickie Lee Jones, 67, were shot to death while at the grocery store on Wednesday. Police have arrested a suspect, Gregory Alan Bush, 51, who is white.

Bush's motives haven't been addressed by authorities, but Jeffersontown police said minutes before he entered the grocery store he tried to get into a predominantly black church. The alleged gunman reportedly told an armed white civilian when leaving the Kroger that, "whites don’t shoot whites."

Court records also show that Bush was accused of calling his ex-wife, who is black, "(N-word) bitch."

Yarmuth, a Democrat, said on social media Saturday that, "hate should have no home in America." He called on federal prosecutors to look into specific details involving race surrounding the case.

Background:Kroger shooting suspect has history of violence, losing gun rights

"As federal officials continue to work with local and state law enforcement in the wake of this week’s senseless Kroger murders, I believe they can and should take into account the racist words and actions of the man behind this gruesome act and call it what it was: a hate crime," Yarmuth tweeted.

Stallard was killed inside the Kroger while standing next to his 12-year-old grandson, sources with close ties to his family have said. Jones was shot and killed in the parking lot.

U.S. Attorney Russell Coleman said this week that federal investigators are "examining this matter from the perspective of federal criminal law, which includes potential civil rights violations such as hate crimes."

Mayor Greg Fischer, also a Democrat, told the Courier Journal on Saturday that he has been in contact with local, state and federal prosecutors about the shooting. Stallard is the father of Kellie Watson, who serves as the mayor's racial equity officer.

Fischer said through a prepared statement that he is "appreciative that this horrific incident is being investigated as a hate crime."

Under the Matthew Shepard and James Byrd Jr. Hate Crimes Prevention Act, offenders who are convicted of deliberately killing victims because of their actual or perceived race, religion, sexual orientation or gender identity may be imprisoned for life.

The federal statute criminalizes violent acts resulting in bodily injury or attempts to inflict bodily injury, through the use of fire, firearms, explosive and incendiary devices, or other dangerous weapons. The law does not criminalize threats of violence, according to the U.S. Justice Department.

Related:Could the Louisville Kroger shooting be a hate crime? Here's how it's defined

Local legal experts told the Courier Journal it is unlikely that Bush, who pleaded not guilty Thursday, will be tried in both federal and state court.

Former federal prosecutor Brian Butler, who is now a defense attorney, noted Bush is facing a potential state death penalty and “given what appears to be very strong evidence against him, the state will likely be able to obtain a very significant sentence.”

Kent Wicker, also a former assistant U.S. attorney, said the Jefferson County Commonwealth’s Attorney’s Office has "a bunch of talented, experienced prosecutors who try murder cases every day. So it’s not obvious why bringing the case as a federal hate crime would be an advantage."

But defendants in some nationally notorious hate crimes nationally have been prosecuted in both state and federal court.

In 2015, Dylann Roof slaughtered nine African-Americans, including a state lawmaker, at a historic black church in South Carolina. Federal prosecutors tried him first, winning the death penalty on 33 counts of federal hate crimes; Roof then pleaded guilty in state court and received nine life sentences.

Both state and federal prosecutors also have filed charges against James Alex Fields, who is accused of plowing his car into protesters last year at a white nationalist rally in Charlottesville, Virginia, last year, killing a woman and injuring dozens more.

Yarmuth, who is running for re-election this year, pointed out on Twitter that he co-sponsored legislation to remove barriers to pursuing prosecution of hate crimes based on race and other factors.

Hate crimes have seen an increase in major U.S. cities for four consecutive years, according to the Center for the Study of Hate and Extremism at California State University.

The center found a roughly 12 percent increase last year in incidents in Chicago, Dallas, Houston, Los Angeles, New York, Philadelphia, Phoenix, San Antonio, San Diego and San Jose, California.

USA Today and reporter Andrew Wolfson contributed to this story. Reporter Phillip M. Bailey can be reached at 502-582-4475 or pbailey@courierjournal.com. Support strong local journalism by subscribing today: courier-journal.com/philb.