Students were held past the normal 2:24 p.m. dismissal time.
Police said Abraham Lincoln Senior High School was also locked down.
Gates Street Elementary began releasing students by 3 p.m.
One person was shot on the 2100 block of Keith Street in Lincoln Heights, according to the LAPD.
Police were searching for a suspect believed to be in the area. Both schools are not within the perimeter search, according to police.
A male shooting victim was hospitalized.
At about 3:50 p.m. police said a suspected gunman was arrested.