The Philadelphia Medical Examiner's Office says 81-year-old Elizabeth Morini died of congestive heart failure.

Tom Morini doesn't buy it. He says he knows his mother was murdered by Victor Vargas, the 24-year-old drug addict who broke into her Kensington house looking for drugs or cash and beat her so savagely that her jaw was broken and cheekbone shattered.

Morini says he remembers his mother before April 2, 2008: an indefatigable widow who refused to move from her rowhouse and piloted her 1985 Oldsmobile to church, the grocery store, the beauty shop, and friends' homes. But that day was her last on the 2800 block of Boudinot Street. By May 21, 2008, she was dead.

On Wednesday, her admitted assailant was sentenced to 20 to 40 years in prison for that attack and four other burglaries or robberies on Boudinot Street. Vargas had pleaded guilty to aggravated assault and burglary at Morini's house; the cause of her death could not legally support a murder prosecution.

"I am not happy," Tom Morini, 51, said after Vargas' sentencing by Common Pleas Court Judge Roger F. Gordon.

"Everything was basically the minimum. He can be out of there in 18 years," Morini added, referring to the credit Vargas gets for his time in prison since his arrest. "My mother lost her life."

Assistant District Attorney Peter Erdely said he, too, was disappointed by the sentence for a man he called "a menace, a predator who remains a danger to the citizens of Philadelphia."

Erdely asked the judge to sentence Vargas to 36 to 73 years in prison, citing 23 adult arrests and nine failures to appear in court.

Vargas, 27, benefited from pleading guilty not just to the Morini break-in and assault but to four other break-ins or robberies that Erdely said he plotted and executed from his house in the same block of Boudinot Street from March 6 to April 8, 2008.

In two burglaries, Vargas hit the home of the same Asian immigrant family, twice cleaning them out while they were at work.

He was arrested April 8, 2008, when a man he robbed chased him down, Erdely said, adding that the final link to the Morini assault came from DNA Vargas left behind.

Vargas entered Morini's bedroom at 4:40 a.m. and hit and threatened her until she told him she had money downstairs. As Vargas went to search, Erdely said, Morini followed, carrying a wooden chair leg she used to prop open a bedroom window.

Erdely said Morini smacked Vargas on the back of the head, drawing blood. He then beat her with a flashlight before fleeing.

Defense attorney Olivia Gabriel told the judge that Vargas' problems were linked to an absentee, alcoholic father and his own intractable addiction to multiple drugs.

Gabriel asked for a 15- to 30-year prison term, citing Vargas's guilty plea.

Luisa Diaz, Vargas' girlfriend and mother of his two children, 7 and 2, also asked for leniency. She called him "a great father. . . . When things were going good, he's great."

Vargas read a brief statement in which he apologized to his victims.