A fourth-grade teacher who worked nearly 40 years in the Los Angeles Unified School District has been arrested on suspicion of sexually abusing 20 students, a year after another veteran teacher accused of molesting nearly two dozen pupils brought national attention to the district and the problem of classroom sex abuse.

After a 10-month investigation, eight felony counts of continual sexual abuse and seven counts of lewd acts upon a child were filed Wednesday against Robert Pimentel, of Newport Beach, for abuse that allegedly took place at George De La Torre Jr. Elementary in the Wilmington area, officer Christopher No told The Associated Press