It’s June 30, 2014 -- just a few months after Vanessa Milligan and her unborn baby were killed -- and Gabriel Vega appears to be finding out for the first time- the baby girl was his.

"She would have been beautiful. That little girl would have been beautiful," Vega said.

A police interrogation video was shown to the jury in Vega’s trial on Monday. He's accused of strangling Milligan and setting fire to her home to cover up the crime. The Troy police sergeant that questioned him took the stand Monday, and said Vega told officers he never saw Vanessa Milligan the night she died.

Detective Jonathan Becker says DNA evidence proves otherwise.

"Listen, I did not do this just 'cause the evidence can prove that I had sex with her," Vega said.

Investigator: "And not just that, the fact that you lied about having sex with her," the investigator said.

"I lied because I was scared," Vega replied.

Vega maintains his innocence in the death of his 19-year-old pregnant ex-girlfriend, and defense attorney Frederick Rench didn’t object to this video shown as evidence. He did object to introducing recorded calls Vega made from jail to his mother and another ex-girlfriend, Kim Virola.

Assistant District Attorney Andrew Botts says Vega tried to hide the calls by first dialing his mother and asking her to call Virola in a three-way phone call. Botts says the content of one conversation includes Vega telling Virola, "If you shut your damn mouth, I’m coming home."

The prosecution discovered these calls last Monday and shared them with the defense on Saturday.

ADA Botts expects Virola to give witness testimony Tuesday, and that’s when he'll try to introduce those calls as evidence. The judge plans to rule on whether or not he’ll allow it at that time.