The girlfriend of accused murderer Randy O'Hagan said that members of the White Boy Posse threatened to kill O'Hagan unless he killed a former gang member.

Chelsey Hart testified Tuesday at O'Hagan's trial in Saskatoon.

O'Hagan is charged with first-degree murder in the fatal shooting of Lorry Santos, a 33-year-old mother of four gunned down in her home in September, 2012.

Lorry Santos

33-year old Lorry Santos was the mother of four children when she was shot and killed in 2012, as she answered the door at her home on Peterson Terrace. (Facebook)

Police have said since O'Hagan's arrest that Santos was the innocent victim of a botched gang assassination.

Deadly road trip

Chelsey Hart said the White Boy Posse street gang ruined her life, and the life of her former boyfriend, Randy O'Hagan.

On the stand, Hart told the court that O'Hagan left his home in Lloydminster on a trip to Saskatoon two days before Santos was murdered. 

He told her he was going to visit an old friend. 

'I didn't want to know anything. I kept my mouth shut.'- Chelsey Hart

When he got back, his story changed.

He told her the Posse had ordered him to kill a former gang member named T.J. Cromartie.

If he didn't, the gang was going to kill Hart and her family. 

O'Hagan told his girlfriend he didn't go through with the deed. However, Hart says she began to connect the dots after hearing about the Santos murder.

"I didn't want to know anything," she said. "I kept my mouth shut."

Police believe O'Hagan was targeting Cromartie, but got the wrong address, shooting Santos by mistake.

Drug deals and OxyContin

Hart said she and her former boyfriend were both drug dealers in Lloydminster, and both of them were addicted to OxyContin, a powerful pain medication.

A month before the murder, Hart said O'Hagan received a suspicious text message on one of the phones used in their drug dealing operation. It talked about a 'hit' on T.J. Cromartie, and listed a $40,000 bounty on his head.

Hart says her life was threatened if O'Hagan didn't end their relationship. At one point, the gang believed she was a police informant.

"They were going to cut my head off and take it to my parents' doorstop," she said.

Earlier in the day, a police forensic identification officer testified how investigators recovered two handguns stashed under a shed in Sutherland.

The guns -- a Glock, and a Smith and Wesson -- were wrapped in socks that were in turn wrapped in three plastic bags. The guns had been partially disassembled. Two clips with live ammunition were also in the bags.

The O'Hagan trial is set to run for three weeks.