Court documents released this week said construction worker Diego Pillco punched Shelly in an argument over the noise he was making, then hanged her from a shower rod to make her death look like a suicide.
The New York Times said Pillco told detectives he lashed her in place using a rope technique he had learned tying up pigs on a farm in his native Ecuador.
Shelly, who appeared in the movies "Factotum and Trust," was found dead in her West Village apartment last month. Pillco was arrested a few days later and has pleaded innocent to the charges.
Pillco, who was arraigned on Wednesday, told police in Spanish he had awoken in a bad mood and that his encounter with Shelly quickly escalated into his slamming the door on her, causing an injury. He said he followed the actress back to her apartment and struck her because he feared he would be deported if she called police.