The evil Queens dad who slashed his baby girls to death because he had already killed their mom and didn’t have car seats to transport them to Mexico pleaded guilty to the murders Friday in a deal that will put him behind bars for 45 years, prosecutors said.

Miguel Mejia-Ramos, 28, already admitted that he killed his wife, Deisy, and then his 1- and 2-year-old daughters in their Jamaica bedroom after searching his wife’s phone in January and finding pictures of her with another man.

He was captured in Texas as he tried to flee to Mexico.

“Justice has been swift and it has been certain,” said Queens District Attorney Richard Brown.

Deisy, 21, and her daughters were butchered after Deisy filed a police report in May saying she feared that her husband would murder them.

But her warning went ­unheeded — because it was in Spanish and never translated, The Post reported exclusively.