The heartbroken mother of Stephanie Moulton gripped a box of tissues as a picture of the 25-year-old North Suffolk Mental Health counselor filled a screen facing jurors on the opening day of the trial of the schizophrenic patient accused of slaying her.

Kimberly Flynn sobbed quietly as the picture flipped to a close-up of her daughter’s ankles and a cop explained how the killer had pulled down Moulton’s pants and underwear.

“We’re learning it as you all are learning it,” Flynn said after testimony ended for the day. “We’re seeing the same thing you’re seeing, as you’re seeing it.”

The dead woman’s father, Bob Moulton, said, “You see her so helpless and you can’t do anything about it.”

Flynn said it’s torture.

“I’m her mom,” Flynn said. “I was supposed to take care of her.”

Deshawn Chappell, a schizophrenic patient at a residential program for mentally ill adults in Revere, is accused of stabbing and beating Stephanie Moulton and slashing her throat on Jan. 20, 2011. Chappell dumped her partially clothed body, wrapped in a sheet and plastic shopping bags, in a church parking lot, prosecutors said.

Chappell allegedly ditched Moulton’s car in Boston, bought new clothes at an A.J. Wright in Dorchester and hopped the MBTA for Braintree. State police captured him as he tried to make his way to his grandmother’s house in Dorchester.

Chappell’s lawyer, Daniel Solomon, said his client is mentally ill. “(He) suffers from schizophrenia,” Solomon said.

Moulton’s murder spurred state officials to take steps to address mental health workers’ safety.

Clifford Robinson, deputy commissioner of the Department of Mental Health, said nearly 2,000 state and contracted provider employees have been trained in “de-escalation” and “behavioral” techniques to defuse potential violence. A safety symposium in Moulton’s honor geared toward direct-care workers is held yearly, Robinson said.

Jason Stephany, a spokesman for SEIU Local 509, pointed to an August settlement between the U.S. Department of Labor and the North Suffolk Mental Health Association, the private contractor that employed Moulton, that included ways to communicate violent threats and determine the “behavioral history” of patients.

“It shouldn’t take a vicious attack or the death of a worker,” Stephany said. “Workplace safety should be of equal concern to all human-service providers across the commonwealth.”