Police in Brazil have arrested a second man over the killing of a US-born missionary in the Amazon rainforest.
They say Rayfran das Neves Sales is the key suspect in the murder of Dorothy Stang, a nun who campaigned for more than 30 years on behalf of farmers.
Another man, Amair Freijoli da Cunha, has been charged with conspiracy to murder. He denies any involvement.
Sister Dorothy, 74, was murdered on 12 February in what police believe was a contract killing.
The army is helping with a continuing search for more suspects in the area.
Suspected gunman
Mr das Neves Sales was arrested on Sunday after a tip-off that he was hiding in thick forest close to the Trans-Amazon highway, the authorities said.
He was found about 35km (20 miles) from the scene of the murder in Anapu, in Para state.
Police accuse him of being one of two gunmen who shot Sister Dorothy at close range.
Also on Sunday, Amair Freijoli da Cunha - who allegedly hired the gunmen at the request of a farmer accused of ordering the killing - was charged after nearly three-and-a-half hours of police interrogation.
He had turned himself in the previous day with his lawyer in Altamira, a town about 130km from Anapu.
He told police he knew the farmer, but denies hiring the gunmen.
Brazilian troops are continuing to arrive in the region to help track down the missionary's killers.
The second gunman is believed to be still hiding in the rainforest, while the accused farmer is thought to have fled the area on a private plane.
Government plea
Brazil's government is under pressure to bring the perpetrators to justice as the case continues to resonate across the country and beyond, the BBC's Steve Kingstone in Sao Paulo says.
The crime has highlighted the often violent conflicts over land in the Amazon, our correspondent adds.
After the murder, the government said it planned to protect a huge swathe of the Amazon.
It said nearly four million hectares (10 million acres) in Para state would become a conservation area in a bid to ward off loggers and landowners.
The government said it also wanted to reinforce the environmental police force.
Sister Dorothy, who was a naturalised Brazilian, had complained that the government was not doing enough to stop land-related violence.