The president of the NAACP Maryland State Conference invited Gov. Larry Hogan and General Assembly members to participate in the national organization's "America's Journey for Justice," an 860-mile mile march from Selma, Ala., to Washington.
Conference President Gerald G. Stansbury said it was "time to send a message that justice is for all, not just a chosen few."
"If you can't march, we ask you to join us in Washington at the final destination, where we will then rally," he said outside the NAACP's Baltimore office.
He said the state conference would be pushing to reform police after the deaths of Freddie Gray and others across the country. Gray, 25, died in April after suffering a spinal injury in police custody.
The NAACP wants to change Maryland's Law Enforcement Officers Bill of Rights, which provides procedural protections for officers accused of misconduct.
The law prohibits supervisors from questioning an officer for 10 days after an incident, among other provisions.
"Citizens, if they see a crime, police want that information right away," Stansbury said. "Police should be held to that same standard. That doesn't require 10 days to do, especially if it's a life-and-death situation. Their story shouldn't be changing from the first day to the 10th day."
The group is also advocating police body cameras, community policing and minority recruitment.
"We want the people in our communities to be the ones building the trust back with the police department," Stansbury said. "We need to all work together and we need to see more minorities involved so the police can go back to supporting the community, hand-in-hand."
The Rev. Todd Yeary, political action co-chair of the Maryland conference, said the group also supports mental health evaluations for officers.
He pointed to the recent case in McKinney, Texas, where an officer was captured on cellphone video shoving a 14-year-old girl to the ground and drawing a gun on two other youths.
"That's a high-stress job keeping them in constant contact with difficult situations," Yeary said. "We need to give them time to de-stress and regroup."
Rion Dennis, the other political action chair co-chair of the state conference, said he hopes the march leads to change in Annapolis.
"We hope to see some meaningful reform come about before January when the session starts again," Dennis said.