Thousands of people are demanding that an additional murder charge be slapped on the Colorado dad accused of slaying his family — for the death of the fetus his wife was carrying.

Over 50,000 people have signed a Change.org petition to charge Chris Watts, 33, with a fourth capital murder charge, in addition to those brought against him Tuesday for allegedly murdering his pregnant wife, Shanann, 34, and daughters Bella, 4, and Celeste, 3.

“Shanann Watts was pregnant with a baby. A baby boy that they had planned to call Niko. When she was murdered so was Baby Niko,” wrote Brittney Brasher, who started the petition to Colorado Gov. John Hickenlooper.

Watts is facing a felony charge of unlawful termination of a pregnancy, because of Colorado’s penalty enhancement laws to protect pregnant women. But Colorado is not among the 38 states with fetal homicide laws.

Former Boulder County District Attorney Stan Garnett told Denver 7 it’s “virtually impossible” under Colorado law to file a murder charge relating to a child who hasn’t been born yet.

“Colorado requires that the child live outside the mother’s womb independently and then be killed as a result of something that occurs then,” said Garnett.

The people signing the petition are calling for a law, to be named “Niko’s Law,” to change that.

Watts admitted to killing Shanann, who was 15 weeks pregnant, but denies murdering their children. He could face life in prison or the death penalty if convicted.