The mother of a Toronto man accused of murdering four people has been arrested on Wednesday, one week after her son was charged for a string of violent crimes.

It is alleged she assisted her son, Mark Moore, in destroying evidence in a homicide and robbery investigation.

On Oct. 19, Moore was charged with several violent crimes, including four counts of first-degree murder, in an investigation connecting almost a dozen unsolved cases from last year.

The secretive "Project Summit" investigation linked the deaths of four Toronto men – Jahmeel Spence, Courtney Facey, Mike James and Carl Cole – to a series of robberies and shootings.

Moore's mother has publicly defended her son, telling CTV Toronto's Tamara Cherry last week that she believes her son is innocent.

"I'm not saying that Mark is perfect," she told CTV Toronto. "But at the same time there still is a vendetta going on."

Hyacinth Moore, 49, of Toronto has been charged with accessory after the fact, obstruction of a peace officer, conspiracy to commit an indictable offence and accessory after the fact to murder.

She is schedule to appear in a downtown court on Thursday.

Three other men were also arrested as part of "Project Summit" and have been charged in connection to an alleged firearms and ammunition trafficking ring.