Police now say they have a suspect in custody in connection with a double homicide on Montreal's South Shore Friday morning.

Neighbours called police to the Longueuil apartment building after hearing screams around 6 a.m. ET.

The bodies of two females, a 13-year-old and a woman in her 30s, were found in the apartment along with two unharmed children.

Police took a 34-year-old man into custody at the scene, initally calling him an "important witness."

Police haven't publically identified the victims or said what the connection between them was.

Stephanie Blanchette said she came down to the scene after her friend failed to pick her up for work. CBC Stephanie Blanchette worked with the victim at a dental clinic in Longueuil. She said they were also good friends.

Blanchette was supposed to get a lift with the victim to work, but her friend never showed up. Blanchette called the house and no one anwsered.

Blanchette struggled to hold back tears as she talked about the victim's struggles in her relationship with her partner.

Others who showed up at the scene were also visibly distraught.

One woman, who was later led into the building by police, cried uncontrolablly. A man collapsed to his knees and audibly sobbed as a police officer tried to comfort him and moved him away from the cameras.

The two surviving children were taken to hospital for psychological care.

Police are still investigating.

With files from The Canadian Press