Updated

A manhunt is under way for a prisoner convicted in two violent sexual assaults who stabbed one of two police escorts and escaped in the Dallas area as he was being transferred from Florida to Nevada.

Police said Tuesday that 42-year-old Alberto Morales somehow obtained a sharp object and stabbed one of the officers multiple times in the back Monday night outside a Walmart in Grapevine.

The Miami-Dade Police detective who was stabbed is in serious but stable condition.

Morales had been convicted of sexual battery and other charges in December in Miami. He was being taken to Nevada to serve two life sentences for aggravated sexual assault.

Miami-Dade Police Director J.D. Patterson Jr. says the inmate was kicked off a flight because of erratic behavior, so the officers had been forced to drive him.