A nurse has been charged with three counts of murder in connection with poisoning deaths at a hospital, Greater Manchester Police said.
Victorino Chua, 48, was held last year on suspicion of tampering with medical records at Stepping Hill in Stockport.
He was questioned on suspicion of three counts of murder and various counts of causing grievous bodily harm.
Police said Chua has also been charged with one count of causing grievous bodily harm with intent, 22 counts of attempting to cause grievous bodily harm with intent and eight offences of attempting to administer poison, under the Offences Against the Person Act.
He will appear at Manchester City Magistrates Court tomorrow.
Police are carrying out an investigation into the contamination of various medical products between June 1 and July 15, 2011 at the hospital.
Eight patients who were poisoned by contaminated products later died.
They were Tracey Arden, 44, Arnold Lancaster, 71, Derek Weaver, 83, William Dickson, 82, Linda McDonagh, 60, John Beeley, 73, Beryl Hope, 70, and Mary Cartwright, 89.
Chua is charged with murder over the deaths of Ms Arden, Mr Lancaster and Mr Weaver.
Chua, a father-of-two from Stockport, was first arrested in January 2012 and later released on bail.
Assistant Chief Constable Steve Heywood said: "Our thoughts continue to be with those people who were deliberately poisoned and their families.
"From day one we made a commitment to those people, as well as the wider community, to thoroughly and robustly investigate what occurred.
"In close to three years we have conducted many painstaking inquiries and engaged with numerous medical experts.
"We are now at a point where we have charged Victorino Chua with a number of very serious offences."