Winnipeg police laid another charge against alleged serial killer Shawn Lamb on Tuesday.

Lamb was in court Tuesday morning to face a charge of sexual assault stemming from an incident between November and December 2011.

Police said a woman met with a man near Jarvis Avenue and Powers Street and was then driven to a secluded area and seriously sexually assaulted with a weapon.

She was able to flee to a nearby business and notify police.

Court documents state the weapon used was an anti-theft steering wheel lock. 

Now, Lamb faces one charge of sexual assault with a weapon in addition to three charges of second-degree murder.

Lamb was charged with three counts of first-degree murder in June 2012 in the deaths of Carolyn Sinclair, Tanya Nepinak and Lorna Blacksmith.

He is scheduled to appear in a Winnipeg courtroom again on Thursday.