Louis Viera maxed out his sentence at Graterford Prison nine days ago and decided to surprise his 21-year-old girlfriend at her Upper Darby apartment yesterday morning, police said.

Instead, it was Viera who was surprised when he found his girlfriend in bed with another man and "just lost it," Upper Darby Police Superintendent Michael Chitwood said.

"He pulled out two knives he carries with him and just started stabbing," Chitwood said.

Viera, 41, stabbed the woman and her 21-year-old lover numerous times - to the point where the woman's organ's were hanging out of her stomach - before he fled on a SEPTA bus to Chester, according to police.

Both victims were taken to the Hospital of the University of Pennsylvania, where they remained in critical but stable condition, Chitwood said.

The bus that Viera used as his getaway vehicle was pulled over by Darby Borough police at 9th and Main streets and he was taken into custody without incident, police said.

Viera, who had been staying at his mother's house in Chester since his release, was sent to prison March 31 for escaping from a halfway house where he was serving time on drug charges, Chitwood said.

He had dated the female victim before his most recent incarceration and the two were still dating when he arrived at her home on Seaford Road near Long Lane about 6 a.m., police said. She was expecting him, but not so early, Chitwood said.

"He decided to take a bus up and rekindle his old flame," Chitwood said. "Instead of taking her to dinner, he stabs her."

The back door of her home was open and he walked up the stairs to her bedroom. When he saw the other man in her bed, he flew into a rage and pulled out a folding knife and a steak knife he carries with him, police said.

"He said he's used to carrying a knife because when he's in prison, everyone carries knives," Chitwood said.

Viera was charged with two counts each of attempted murder, aggravated assault and related offenses and was to be arraigned late last night, Chitwood said.