A man fatally shot in Baltimore is the city's 40th homicide victim this month, a record month for slayings.

Police say they were called about 8:45 p.m. Friday for reported gunshots. When they arrived, officers found a man shot in the underarm. Police spokeswoman Lt. Sarah Connolly said Saturday that 23-year-old Justin Mensuphu-Bey died about an hour later.

Arrests have dropped sharply in Baltimore since Freddie Gray died on April 19 of injuries he suffered in police custody. Gray's death unleashed protests, riots, and the criminal indictment of six officers.

Homicides were increasing in Baltimore even before Gray's death. But the 40 slayings in May mark a major spike, after 22 in April, 15 in March, 13 in February and 23 in January.