MURRIETA, Calif. -- Two teachers at high schools in southwest Riverside County were under arrest on suspicion of sexual improprieties with students in separate cases, authorities said Friday.

Crissy Torcella Hisey, 28, who was a 10th-grade English teacher at Vista Murrieta High School, is accused of having a sexual relationship with a 17-year-old girl who was not in her class.

Jack W. McLaughlin, 71, a tenured teacher who taught theater at San Jacinto High School, is accused of molesting a boy at his school. It was unclear whether the alleged victim was his student.

Both teachers were arrested Thursday.

Hisey was released on bail, but has resigned from her teaching position, according to Murrieta Unified School District officials.

McLaughlin remains in custody in lieu of $50,000 bail, pending arraignment Monday at the Murrieta Courthouse. He has been put on administrative leave from his job, according to officials at the San Jacinto Unified School District.

The alleged victim told investigators at the San Jacinto sheriff's substation on Thursday that McLaughlin had been molesting him for about nine months, beginning when the boy was under 14 years old, said sheriff's Lt. Kevin Vest.

McLaughlin was arrested when he showed up at Rancho San Jacinto Park about 5:15 p.m. Thursday, said Vest.

"We had arranged to have him come to the park," Vest said.

He was charged with two counts of oral copulation with a person under 16 and four counts of lewd and lascivious behavior with a child under 14, said sheriff's Sgt. David Kurylowicz.

Vest said McLaughlin has no prior convictions and no other victims had come forward.

"At this point in time, we're still investigating," Vest said.

Diane Perez, an assistant superintendent at the San Jacinto Unified School District, said she heard about McLaughlin's arrest after school hours Thursday.

She said parents and students were told about the arrest after school let out Friday at noon.

"This is devastating our district," Perez said. "We're all just grieving right now."

In the other case, Hisey and the girl were contacted by Murrieta police and brought to the police station for interviews, where they said they'd had an ongoing sexual relationship for the past several months, said Murrieta police Sgt. Jim Ganley.

Hisey was booked into the Southwest Detention Center on suspicion of oral copulation by force and sending harmful matter to seduce a minor.

She was released on $25,000 bail, pending arraignment May 30, according to sheriff's jail records.

Hisey had taught at the school since the fall of 2004, when she was a newly certified teacher, said Karen Parris of the Murrieta Unified School District.

"Effective today, she has submitted her resignation," Parris added.

Parris said the school district does strict background checks on all its employees and the Department of Justice notifies school districts if any employee is arrested.

"There was never any reason to suspect any inappropriate conduct," Parris.

However, according to the mother of a senior at Vista High, her daughter said that when school officials told them about the arrest, students were not surprised because the teacher and the girl, who was described as "withdrawn," had been spending a lot of time together.

The school district was offering counseling to any student who needs to speak with professionals. The students are in the middle of their standardized testing, Parris said.

"It's just a very sad and very unfortunate situation for everyone involved," Parris said.