SAN BERNARDINO >> Two adults and an 8-year-old child are dead and another child was wounded in an apparent murder-suicide Monday at North Park Elementary School.

Cedric Anderson, 53, of Riverside came to the school shortly before 10:30 a.m. on Monday, police say.

“He simply said he was there to drop something off there with his wife,” San Bernardino Police Chief Jarrod Burguan said at an afternoon news conference.

Anderson went to his wife’s classroom. Karen Elaine Smith, 53, was there with two aides and 15 special-needs students between first and fourth grades. The pair had been married since Jan. 28, but had already been separated for several weeks, Burguan said.

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“Without saying anything, armed with a large caliber revolver, he opened fire on his wife,” Burguan said. “She was killed in the exchange.”

Anderson emptied the six-shot .357 Magnum revolver and reloaded using a speed-loader firing at least one additional round.

Student Jonathan Martinez, 8, and another student, who has not been identified, were behind the teacher and were also shot. Jonathan was airlifted by the San Bernardino County Sheriff’s Department to Loma Linda University Medical Center, where he later died of his injuries. The second child, a 9-year-old boy, was in critical but stable condition as of 3:30 p.m. Monday.

• Photos: Three dead, one wounded in San Bernardino school shooting

Police do not believe Anderson intentionally targeted the children. And, San Bernardino City Unified School District Superintendent Dale Marsden said, all district policies were complied with when Anderson was let onto campus.

“After that exchange, the suspect turned the gun on himself and killed himself,” Burguan said.

The school, at 5378 H St., was locked down.

About 150 police officers from the San Bernardino Police Department, San Bernardino County Sheriff’s Department, San Bernardino City Unified school police, Rialto Police Department and California Highway Patrol responded to the shooting, along with the San Bernardino County Fire Department.

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North Park students were evacuated to Cal State San Bernardino and then shuttled to Cajon High School, after their parents arrived and showed proof of identification.

In the meantime, North Park students were made comfortable in a university gym, with sandwiches, movies, games and glow sticks, as well as Sherlock, the San Bernardino Police Department’s community affairs dog. North Park educates about 531 students, according to the California Department of Education.

“I am still a little shaken up,” school board vice president Abigail Medina said. “A lot of (school board members) have our children in the school district, so it hits home. It’s a terrible incident.”

Medina said she has three children attending schools in the district, none of them at North Park.

Former San Bernardino City Unified school board member Judi Penman said the school’s police department “is very well prepared” for situations such as the shooting Monday.

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“It is one of the most organized and well-prepared police departments around,” she said. “It interacts and trains with the city police department, and they are well prepared for this type of situation.”

School police previously worked with city officers in the Dec. 2, 2015, San Bernardino terrorist attack. Echoing that day, a call came from the White House and Gov. Jerry Brown called to offer condolences and aid, San Bernardino Mayor Carey Davis said during the news conference.

North Park Elementary will be closed for at least Tuesday and Wednesday. All other district schools will remain open.

Also, connected to Monday’s school shooting, a Riverside home was surrounded by a police SWAT team early afternoon Monday. The unit used a loudspeaker to draw out any occupants, then left with one person who came out of the Mt. Wasatch Drive home in the Orangecrest gated community, a neighbor said.

Superintendent Marsden has a message to parents at the district.

“I would like you to work with your young child to keep things as normal as possible,” Marsden said. “Be willing to listen to their story as many times as possible. And be ready to model for them a healthy response.”

Staff writers Richard De Atley, Brian Rokos, Doug Saunders, and Beatriz Valenzuela contributed to this story.