Erica Caporaletti, a 22-year-old student at Towson University, and Warner DePriest, a 29-year-old D.C. resident, were writing “Black Pre-Born Lives Matter” with chalk on the sidewalk when police arrested them.

The arrests happened just before 6 a.m., soon after a group of about two dozen people, led by the antiabortion advocacy group Students for Life of America, showed up to paint in the street of the 1200 block of Fourth Street NE as part of what they called a campaign to highlight the impact of abortion on Black communities.

Tina Whittington, executive vice president of Students for Life of America, said police first warned that they would detain the group if they painted the street and then told them they could not write on the sidewalk with chalk.

Caporaletti and DePriest began to write faster when police moved to arrest them for defacing public property, rushing through the word “Pre-Born” when officers approached them, according to a video taken by the protesters. They were arrested and held for about an hour before returning to the scene to condemn the city for its response to their protest.