Shocking video from a hidden camera captured three Calgary careworkers brutally assaulting an elderly resident less than a month before he died, court heard Thursday.

Crown prosecutor Susan Kennedy told provincial court Judge John Bascom the footage was taken after Ulrich Wissner, 92, complained to his family he was being mistreated at a CareWest facility.

“In the fall of 2013, Wissner’s family noticed a change in his personality,” Kennedy said, reading from statements of agreed facts for all three offenders.

“When family members enquired with Wissner he advised them that staff were hurting him,” she said.

“Wissner’s complaints to his family members increased over time.

“By January, 2014, Wissner pleaded with his sons not to leave him on his own,” Kennedy said.

Because of his father’s concerns, Peter Wissner installed a motion activated camera in his dad’s room on Feb. 3, 2014.

Four days later it captured Maria Dumo, Angelina Borja and May Casimero assaulting the elderly resident, Kennedy said.

All three pleaded guilty to assault in connection with the Feb. 7, 2014 incident.

Dumo was seen at two separate times that day menacing the elderly Wissner, who was bedridden, very physically frail and suffered “contractors” that seized up his muscles into rigid positions.

Shortly before 7 p.m. Dumo entered Wissner’s room to pick up his dinner tray.

As she did so, she dipped a fork into a cup and flicked water at Wissner five times before holding the cup over his head and threatened to pour it on him.

Shortly after 10 p.m, all three entered Wissner’s room where Dumo and Borja forcefully held Wissner while Casimero changed his diaper.

Borja and Casimero also used excessive force to change Wissner’s nightgown and Borja slapped him twice on the shoulder and flipped him the finger while standing at the foot of his bed.

The video also showed Casimero holding Wissner’s catheter bag of urine over Wissner’s face, threatening to pour it on him.

At the request of defence counsel, Bascom ordered presentence reports on all three accused prior to their return to court in July.

Outside court, Peter Wissner expressed dismay at the treatment of his father, who died March 6, 2014.

“I was probably the most shocked when I pulled that video card out of that camera,” he said, adding both CareWest, which fired the trio, and police acted swiftly.

“They worked very hard to press charges before my dad died,” he said.

kevin.martin@sunmedia.ca

On Twitter: @SUNKevinMartin