Prosecutors have told court a man accused of murdering a Saskatoon mother was contracted for the killing by a gang.

Closing arguments wrapped up Wednesday in the first-degree murder trial of Randy O'Hagan, who is accused of firing shots at a home that killed Lorry Santos in September 2012.

The trial has heard that the mother of four's home was mistaken for the home of a former Alberta gang member, due to a mix-up over text messages.

The Crown argued the killing was planned, contracted and was done at the direction of a criminal organization -- the White Boy Posse.

The defence argued O'Hagan wasn't paid for the killing but was told to do it without the promise of money.

A decision on the case will be made May 22.

The defence offered no other theory of how Santos was shot when she answered her door.

Court earlier heard testimony that the intended target was a former member of the White Boy Posse who witnesses say had a bounty on his head.

John Marshall, a forensic firearms specialist for the RCMP, was the final person to testify on Wednesday.

Marshall confirmed cartridges found at the scene of the Santos house matched two handguns that were allegedly used.