A day after allegedly killing a 96-year-old patient in a Woodstock, Ont., nursing home, Elizabeth Wettlaufer set sail on a 10-day Caribbean cruise, CBC News has learned.

Mary Zurawinski was a patient at the Caressant Care long-term care facility where Wettlaufer worked when she died on Nov. 7, 2011. Police allege Zurawinski was one of eight elderly patients killed by Wettlaufer, 49.

The day after Zurawinski's death, Wettlaufer and her partner boarded the Emerald Princess in Fort Lauderdale, Fla., and spent 10 days cruising the warm, teal waters of the Caribbean.

They snapped photos of the massive cruise ship, which boasts of "casual elegance" with multiple pools, nightclubs and a spa. The couple snapped pictures of their stops in St. Thomas, U.S. Virgin Islands and Aruba.

Wettlaufer boarded the Emerald Princess the day after Mary Zurawinski, 96, was allegedly murdered. (Facebook)

Trish Crosbie knew Wettlaufer and her partner well at the time. A couple of days after the cruise, the couple visited her home to drop off souvenirs for Crosbie's infants. Wettlaufer "held them, she played with them," she told CBC News, adding "she seemed at that point in good spirits."

Zurawinski was the third of three patients Wettlaufer allegedly killed in the days and weeks leading up to the Caribbean cruise in 2011. Police said Helen Matheson, 95, was killed on Oct. 27, and Gladys Millard, 87, died on Oct. 14.

When contacted, a distant relative of Zurawinski told CBC News that the 96-year-old was "a lovely woman" whose husband and sons passed away years earlier.

Affected by patient's death

Around the time the three patients died, Wettlaufer was a frequent visitor to Crosbie's home. On one occasion, Crosbie said, Wettlaufer "was acting very quiet and standoffish" about the recent death of a patient. Crosbie said Wettlaufer "seemed upset at the fact this person passed away. But she was not very, wanting to give out too much information. I asked her, 'How did this person die?' She said, like, 'I'm not sure.'"

Trish Crosbie says Wettlaufer appeared 'in good spirits' after a vacation the nurse embarked on just one day after Mary Zurawinski died. (Chris Mulligan/CBC)

"Normally she's overly pushy, trying to get your attention, saying, 'Look at me, look at me.' This time she was very quiet and not wanting to talk to people, and just like, almost depressed."

Crosbie told CBC News, "Looking back on it now, I wonder if she was … reflecting on something she may have done … we'll never know for sure."

Former partner in Quebec

Wettlaufer's partner was a woman about a decade older than her. They were together for several months and shared Wettlaufer's Woodstock apartment until they split not long after the cruise.

CBC News recently located Wettlaufer's ex-partner in a small Quebec village where she now lives. When approached, the partner said repeatedly, "I don't want to get involved in this at all." She did confirm, though, that Wettlaufer had talked about harming people, but said her former partner has suffered from mental health issues, including addictions to alcohol and prescription pills.

The former partner also told CBC News that Woodstock police contacted her recently after finding her phone number on Wettlaufer's mobile phone. She wouldn't say when she last spoke with Wettlaufer or what, if anything, she told police.

Wettlaufer is pictured vacationing in Niagara Falls. (Facebook)

The couple had a tumultuous relationship, according to acquaintance Cheryl Schwartz. Wettlaufer "was very pushy about things. [They] argued a lot," Schwartz said.

However, in August 2011 the couple's relationship was still strong. They spent time in Niagara Falls and snapped photos as they toured local attractions together. At one point, Wettlaufer posed inside a mock barrel that looks like it's about to plunge over Niagara Falls. She also posed in a fake electric chair. By then, police claim, Wettlaufer had already killed twice.

Wettlaufer poses in a mock-up of an electric chair in Niagara Falls. (Facebook)

After the three deaths in the fall of 2011, Wettlaufer allegedly did not kill again until July 2013. It's not clear where she was during the 20 months in between.

CBC News has learned Wettlaufer left her staff job at Woodstock's Caressant facility after run-ins with management. She later began working for the Lifeguard Home Care — an agency that supplies nurses and other services to homes and care facilities.

She left that job and went to work for the St. Elizabeth's staffing agency. She's alleged to have killed Helen Young, 90, in July 2013 and Maureen Pickering, 79, in March 2014. The final alleged victim died in August 2014 at London's Meadow Park facility, where Wettlaufer was working at that time.

While the eight alleged murders date as far back as 2007, Wettlaufer was only arrested last month after she allegedly provided information about the crimes to staff at Toronto's Centre for Addiction and Mental Health.

Before being formally charged, police obtained a peace bond prohibiting Wettlaufer from possessing insulin. Police claim Wettlaufer used a drug to kill all eight patients.