The shooting occurred shortly after 10 a.m. during a wedding at New England Pentecostal Church in Pelham, N.H., near Manchester, said Pelham Police Chief Joseph Roark.
Roark said wedding guests had pinned down the suspect by the time they arrived, and he is in custody.
Approximately 40 people were in attendance at the wedding, according to Roark.
Two people with gunshots wounds were transported to hospitals and a third person with minor injuries was also taken to the hospital, Roark said.
Roark did not release identities of the victims or suspect.
Roark said that “preliminary investigation” has shown the shooting “does not appear to be random.”
Churchgoer Janail Archer said his father, Othniel Archer, 59, a deacon there during the shooting, told him that among two shot, was the church leader, Bishop Stanley Choate and a woman.
Othniel also told his family he jumped from the balcony to subdue the shooter with the help of three others who “tackled” him to the floor.
He also told family he recognized the gunman as the stepson of Luis Garcia, a Manchester minister fatally shot on Oct. 1 inside a Londonderry home, New Hampshire Union Leader reported.
“My dad was very close with the family,” Archer told the daily newspaper of Manchester.
Funeral services for Garcia, 60, were scheduled to take place after the wedding ceremony, but the service was canceled, police told Geraldo Pagan, a friend of Garcia’s, who had arrived for the funeral.
“We were very shocked,” Pagan said.
Brandon Castiglione, 24, of Londonderry, has been charged with second-degree murder in connection with Garcia’s death.
Archer told the New Hampshire Union Leader that Castiglione’s father, Mark Castiglione, was part of the couple getting married Saturday.
Local police have turned the criminal investigation for Saturday’s shooting over to investigators with the New Hampshire Attorney General’s Office and New Hampshire Police Major Crime Unit.
New Hampshire Sen. Maggie Hassan tweeted that she was ‘deeply disturbed’ by the incident.
“I’m deeply disturbed to hear about the shooting in Pelham this morning,” Hassan tweeted. “Today was supposed to serve as a celebration of the life of Minister Luis Garcia. This senseless violence can’t continue — my prayers are with the victims of this terrible attack.”