The construction worker who killed Adrienne Shelly in her West Village office pleaded guilty to manslaughter - and gave new details about why he killed the actress-director. Diego Pillco will receive 25 years in prison; as an illegal immigrant from Ecuador, the Post says his sentence will be "almost certainly followed by deportation."

Originally, Pillco had told the police he killed Shelly in November of 2006, he was in a "bad mood" and picked a fight with her, because she had complained about construction noise he and other workers had been making. Pillco had pleaded not guilty shortly after the murder, but, perhaps fearing a trial and murder conviction with life sentence, he now says he killed Shelly because she caught him stealing from her purse. Pillco had apparently seen Shelly in the elevator and decided to rob her; he watched her go into her apartment, leaving the door open. From the Daily News:

During the struggle, Pillco muffled Shelly's screams by covering her nose and mouth "out of despair" until she passed out.

"She fell to the floor, and I was very scared," Pillco whispered in Spanish. "When she fell to the floor, I saw a sheet, and I decided to choke her."

Police sources also believe he may have intended to sexually assault her.

Shelly's husband discovered her body hanging from a shower curtain rod, suggesting suicide. But friends and family doubted that Shelly would kill herself with a young daughter and a film, Waitress, that had just been accepted at the Sundance Film Festival. Further police investigation revealed that she was murdered and her body had been staged to look like a suicide - they found a dusty boot print on the toilet seat - a print that matched Pillco's.

At yesterday's hearing, the prosecutor had told Manhattan Supreme Court Justice Carol Berkman that Shelly's family agreed to the plea. But the judge, noticing the "grim faces" of Shelly's husband and relatives, said, "Well, I’m not going to ask whether they’re happy with this."

And Pillco said, "I just want to ask for forgiveness to the family." The Post reported one of the Shelly's brothers "broke into angry laughter" and Shelly's mother Elaine Langbaum said, "No! No!" with her fists clenched. Judge Berkman told Pillco, "I don't think you'll get that sir."