The Houston Independent School District has uncovered evidence that teachers at two elementary schools helped students cheat on state exams, and educators at two other campuses offered questionable assistance.

In the most serious cases, students from Lockhart and Cornelius said teachers alerted them to wrong answers on high-stakes exams, and an analysis of test booklets from Cornelius showed suspicious erasures changing wrong responses to right ones.

The probes also raised questions about the actions of teachers during testing at Tinsley and Scott elementary schools but found no outright cheating, according to HISD reports released to the Houston Chronicle in response to a public records request.

The findings — which center on the past two years — emerge as the Texas Education Agency completes its own investigation into possible cheating at HISD schools this year. District officials said the state has flagged 14 unnamed campuses.

A TEA spokeswoman said that, based on HISD's own investigations, the agency does not see an unusual pattern of cheating in the state's largest school district. But district Superintendent Terry Grier, who has called for third-party investigations into all alleged testing irregularities, vowed to oust teachers who cheat and said the district will consider placing monitors in all classrooms during testing.

"This is an issue of ethics, plain and simple," Grier said. "Just because you can earn a bonus for students doing well is no reason to cheat. We've made it very clear that we will not tolerate cheating here, and if people get caught that they are going to get terminated and reported to TEA."

Since 2007, HISD has distributed performance bonuses — up to $10,000 in some cases — based on students' scores on standardized tests.

Texas was at the center of a cheating scandal several years ago, and recent investigations from Atlanta to Washington, D.C., have renewed questions about high-stakes exams that can cost teachers their jobs.

"How many wake-up calls have they had?" Robert Schaeffer, of the anti-testing National Center for Fair & Open Testing, asked of HISD. "When people's careers, income and self-images depend on boosting test scores, some will find ways to boost scores by any means necessary."

No 'unusual pattern' seen

TEA monitored testing in the spring at some of HISD's 300 campuses after the agency confirmed cheating at Key Middle School. District officials estimated that no more than five state monitors were present during any test day.

TEA spokeswoman Debbie Ratcliffe said agency officials weren't troubled by results of the district's recent investigations into test irregularities.

"It doesn't seem like an unusual pattern to us because a district that size is likely to have allegations," Ratcliffe said. "The reality is, with that many staff and kids involved, something's going to go awry. We don't see any cause for alarm there."

At Cornelius Elementary, investigators from an outside law firm found evidence that a fifth-grade teacher, Willie Jones, helped students cheat on the TAKS science test in 2010.

The report noted that 71 percent of her students made perfect scores - outperforming classmates who made better grades in class - and an analysis of their test booklets found that up to 10 answers were changed from wrong to right in some cases. Students said Jones told them when their answers were wrong and pointed to right ones.

'Vast majority' honest

The investigation, prompted by a tip from a parent, also found evidence of cheating in previous years.

Jones retired from the district in lieu of termination last February while the investigation was ongoing, according to the report and HISD officials. Another teacher implicated has been proposed for termination.

Jones could not be reached for comment Wednesday.

A teacher from Lockhart Elementary faces sanctions after investigators concluded she helped students cheat, tapping them on the shoulder, pointing out wrong answers and making comments such as "Are you sure?" Some students said she didn't give them the answers, but investigators concluded that, "on balance," cheating occurred.

The Lockhart principal has recommended that the teacher keep her job but no longer give the TAKS test. That decision is under review by senior HISD officials.

At Tinsley Elementary, investigators found that two of 29 students copied a writing sample from a book or computer on a state test for limited-English students. Another essay showed evidence of editing. Investigators suggested the teacher wasn't appropriately monitoring her students. The test is mandatory, but does not factor into the state's school ratings.

Essays on the high-stakes TAKS test from a fourth-grade class at Scott Elementary raised flags with the TEA because of their similarity. HISD's investigators found that the teacher taught his students to follow a formula and memorize possible sentences. The report suggested the district discourage formulaic writing.

Grier said it was important to note that most teachers were honest.

"We've got 13,000 teachers and the vast, vast majority of them never consider cheating," the superintendent said. "It's very unfortunate when you have the actions of some impacting the reputations of so many others."

ericka.mellon@chron.com