COVINGTON - A Louisiana prosecutor says a former high-school math teacher and assistant girls' basketball coach has pleaded guilty to molesting a 16-year-old girl who had sent him Twitter messages.

St. Tammany Parish District Attorney Warren Montgomery said in a news release Wednesday that 38-year-old William Leto of Bush was sentenced Monday to five years in prison without parole.

Leto taught and coached at Fontainebleau High School in Mandeville. Montgomery says he pleaded guilty Monday to molestation of a juvenile by a teacher.

The prosecutor says the St. Tammany Parish Sheriff's Office received an anonymous tip last year that Leto was having an inappropriate relationship with a 16-year-old student. Montgomery says investigators learned that Leto's contact with the student began on social media and turned sexual.