Rosemary Sloan-Sims smiled as she recalled the tender hug her daughter had given her at their family reunion a month ago. Johnette Sims had been teasing her that night, Sloan-Sims said, and came up behind her as she talked to her grandchildren.

“She just grabbed me,’’ Rosemary said, and she reached out with her own arms as if she were back in that moment.

Her voice turned to a wail as she repeated her daughter’s words: “Mama, I love you!’’

Johnette Sims, 46, was killed Saturday night when, prosecutors say, an alleged drunk driver, 39-year-old Anthony Buchanan, sped down Morton Street in Mattapan at about 80 miles per hour and smashed into her as she walked in a crosswalk, stopped for a few seconds, and took off again.

Buchanan was held on $5,000 cash bail Tuesday in West Roxbury Municipal Court after pleading not guilty to charges including motor vehicle homicide while operating under the influence and leaving the scene of a collision causing death.

Suffolk County Assistant District Attorney Tai Antoine said the 10:30 p.m. Saturday crash was captured on a GoPro camera strapped to the helmet of a scooter driver who told officials Buchanan almost hit him, too.

The camera footage showed Buchanan’s car pass the scooter on Morton Street, traveling in two lanes of traffic, according to court documents. Buchanan allegedly braked and veered right as he reached the crosswalk, and the video showed items flying up into the air, the documents say. As the scooter rider got closer to the crash, the video showed a body sliding along the road next to Buchanan’s car as it came to a stop, the document says.

But after stopping briefly, Buchanan allegedly fled, driving up Morton Street and onto American Legion Highway.

Investigators got the license plate from the video, and discovered that the car was a rental allegedly driven by Buchanan. When they went to his address, he was not home, but his mother was. Shortly afterwards, Buchanan turned himself in to police.

He told investigators he had been at a cookout before the crash, drinking Remy Martin cognac, Antoine said. He allegedly still smelled of liquor when they spoke, she said.

State troopers assigned to the Suffolk district attorney’s office led the death investigation because the crash occurred on a state roadway.

Buchanan’s attorney, Christopher P. Belezos, argued that his client was a churchgoing man with no criminal record. His mother is the Rev. Laura Buchanan Ahart, pastor at United Baptist Church in Jamaica Plain, Belezos said. She is well-known for her work ministering to prisoners in Boston.

Buchanan holds a bachelor’s degree from Johnson C. Smith University, Belezos said, and works as an accountant at the AIDS Action Committee.

“It’s a difficult time for everybody involved,’’ said Belezos after the arraignment. “It’s a very difficult time for his family, and their hearts go out to the deceased’s family as well.’’

Antoine requested $15,000 cash bail, but Judge Mary Ann Driscoll imposed $5,000.

After the arraignment, Buchanan’s supporters walked past reporters outside of court without commenting.

Sims’s family members said they were not swayed by Buchanan’s good family background, saying it had not stopped him from allegedly getting into his car and driving, instead of summoning an Uber.

“I will be honest with you,’’ said Sims’s son, Tyquan Harrell, 20. “I cannot forgive that man for what he did to my mom.’’

Harrell said that since his mother died, he had been restless and unable to eat much. He was in shock, he said. But his family is close, and his mother raised him and his brother right, he said.

“She brought us into this world, and we’re little pieces of her,’’ he said.

Relatives said it was difficult to see Buchanan, and they were upset at his low bail.

“We lost a sister, we lost a relative, we lost a friend,’’ said Sims’s sister, Chevelle Sloan. “It was a weekend for him. My sister is gone for a lifetime.’’

Sims’s mother, Rosemary Sloan-Sims, said she has forgiven Buchanan.

“Not forgiving him would hurt me more,’’ she said. “I know that she is in heaven and that she’s OK. Everything she lost in that wreck, she has it all.’’

Evan Allen can be reached at evan.allen@globe.com. Follow her on Twitter @evanmallen.