DALLAS (AP) _ A man was sentenced to life in prison Friday for raping a woman after immobilizing her with jolts from a stun gun.

Robert Charles Grunsfeld, 27, was convicted Thursday of aggravated sexual assault in an attack on a 21-year-old woman during a date last November.

Two other women testified during the sentencing phase of the trial that Grunsfeld had raped them in May and June after using handcuffs and tear gas to immobilize them. He is awaiting trial in those cases.

During the trial, a former student at the University of North Texas testified that she agreed to go out with Grunsfeld after meeting him at a nightclub.

About a week later, in early November, Grunsfeld took her to dinner with another couple, then invited her to his parents' home for cocktails and to watch videotapes.

Minutes after arriving, Grunsfeld became violent, the woman testified. When she resisted, he pulled an electric stun gun from his clothing and shocked her repeatedly on her arms, back, legs and stomach to subdue her, she said.

Defense attorney Robert Lively said he planned to appeal the conviction, adding that he would try to show that prosecutors withheld evidence.