Toronto murder suspect Bruce McArthur has been charged with three more counts of first-degree murder in addition to the two counts he was charged with earlier in January.

The new charges are in connection to the deaths of Majeed Kayhan, Soroush Mahmudi and Dean Lisowick. The earlier charges were connected to the deaths of Andrew Kinsman and Selim Esen.

As new details emerge about the case, here鈥檚 what we know so far about the 66-year-old landscaper police said could be characterized as a 鈥渟erial killer.鈥

McArthur was arrested on Jan. 18 and charged with two counts of first-degree murder in the presumed deaths of Andrew Kinsman, 49, and Selim Esen, 44, the following day. Kinsman was last seen in late June, while Esen disappeared in mid-April.

On Monday, police held a press conference to announce the latest charges against McArthur and update the public on the investigation.

Police said McArthur worked as a self-employed landscaper in the Toronto area and is known to have worked at 30 different properties within the city. At this point, investigators said they have searched the majority of them.

The remains of at least three unidentified individuals were discovered in the backyard of a residence located on Mallory Crescent, which McArthur used for storage, Det. Sgt. Hank Idsinga told reporters on Monday.

鈥淲here we鈥檝e recovered the bodies are from large planters and they鈥檝e been hidden in the bottom of these planters,鈥 Idsinga said.

Police said they have seized many planters and that there are at least two sites that investigators would like to excavate for bodies.

In addition to the 30 properties where police believe McArthur may have worked, investigators are also thoroughly searching his apartment in a high-rise in the city鈥檚 Thorncliffe Park neighbourhood for evidence. On Jan. 18, they also combed through a rural property belonging to McArthur, located in Madoc, Ont. in eastern Ontario.

Joanne Irvine, a neighbour of McArthur鈥檚 property in Madoc, told CTV News Channel that she noticed a large police presence at the property on the day he was arrested. She said the police were focused on searching the back of his land, which is approximately 20 acres.

鈥淚 don鈥檛 know him personally because he鈥檚 just new,鈥 she said on Jan 19. 鈥淗e would be friendly enough to wave, but he was always busy.鈥

McArthur was busy tending to his 鈥渆laborate鈥 gardens in front of his house or caring for birds that he raised in an out building on the property, according to Irvine.

鈥淗e was always out there gardening and tinkering about,鈥 she said. 鈥淵ou would always see him just on the property alone.鈥

Irvine said McArthur mostly kept to himself and the most of the members of the community hadn鈥檛 had a chance to meet him yet.

鈥淲e knew the guy that sold it [the property] to him and he did say the man was looking for privacy because he had these birds that he raised,鈥 Irvine said.

When he wasn鈥檛 tending to his gardens or caring for his birds, McArthur was also active on a number of online dating sites, according to police. Two of his victims, Esen and Kinsman, also frequented the sites, police said.

It鈥檚 believed that McArthur and Kinsman had a sexual relationship for some time, but it鈥檚 unclear what his relationship with Esen might have been, police said.

On the dating site 鈥淪ilver Daddies,鈥 a profile for McArthur reads 鈥淛ust here to see what鈥檚 out there and maybe make a few new friends鈥 I can be a bit shy until I get to know you, but am a romantic at heart.鈥

In December, Toronto police issued a warning about dating apps, such as Tinder or Grindr, in relation to the disappearances of Esen and Kinsman.

Although police initially identified a link between Esen and Kinsman because they both went missing from Toronto鈥檚 gay village, the latest evidence pertaining to the three new victims means the investigation has been broadened beyond the neighbourhood.

鈥淚t certainly encompasses more than the gay community 鈥 it encompasses the city of Toronto,鈥 Idsinga said.

The police task force investigating the deaths of Kinsman and Esen have been sharing information with another task force looking into the disappearances of three other men from the village in 2012, police said earlier this month. One of those men, Majeed Kayhan, was identified as the one of McArthur鈥檚 alleged victims on Monday.

Last week, CTV News learned that McArthur had been previously convicted of assault. Court documents showed that he was found guilty of one count of assault causing bodily harm and one count of assault with a weapon in connection with an incident in 2001.

McArthur was given a two-year conditional sentence and ordered to receive counselling in 2003. He was also banned from visiting Toronto鈥檚 gay village and from associating with male prostitutes.

A Facebook profile belonging to McArthur, which has since been taken down, offers other clues about his life; for example, he often posted recipes, images of animals, and trending videos. He was also pictured in photos with friends out in the village or at other events around the city. One photo McArthur posted showed a large group of people celebrating Nowruz, the Iranian New Year.

A number of photos on his profile appear to show McArthur dressed up as Santa Claus and posing for photos in a mall setting.

According to his bio, McArthur attended Fenelon Falls Secondary School in the Kawartha Lakes area.

On McArthur鈥檚 list of Facebook 鈥渇riends,鈥 one of the men who went missing in 2012, Skandaraj 鈥淪kanda鈥 Navaratnam, was displayed as one of his connections.

As the investigation continues, police are encouraging anyone else who may have employed McArthur to come forward. Police said they believe there are more victims, but would not speculate as to how many.

None of the murder allegations have been tested in court.