Two and a half years after his death, the miracle of science has made slain NYPD Detective Wenjian Liu a father, CBS New York reports.

The NYPD said Liu's widow, Sanny Liu, gave birth to a baby girl named Angelina on Tuesday. Detective Liu's parents, Wei Tang Liu and Xiu Yan Li, were there as Sanny Liu gave birth at NewYork-Presbyterian/Weill Cornell Medical Center, police said.

Sanny Liu, the widow of slain NYPD Detective Wenjian Liu, gave birth to their daughter, Angelina, on Tuesday, July 25, 2017. NYPD

On Dec. 20, 2014, Liu and Detecitve Rafael Ramos were both shot to death while sitting in their cruiser in Brooklyn.

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The gunman, Ismaaiyl Brinsley, then killed himself with the same weapon. He had posted on Instagram that he wanted to put "wings on pigs" and referenced Eric Garner, whose police chokehold death led to protests against the NYPD.

Police said Detective Liu and his wife had always planned to have children, but their plans were cut short when the detective's life was taken. But on the night of the incident, she asked that her husband's semen be preserved so that she might one day have a child.

The night after Detective Liu was killed, his wife had a dream that he handed her a baby girl, police said.

"I got pregnant through the [in-vitro fertilization] procedure," Sanny Liu said in a news release, "and I told my friend, 'It's going to be a baby girl.' My friend said, 'No, you haven't even checked the sonograms,' but I was right!"

Sanny Liu said she cannot wait to tell Angelina that her father was a hero, and is looking forward to introducing her daughter to the "big blue family" of the NYPD.