2,597. Shechita From Which One Can't Eat

Hilchos Shechita 12:5

If one person slaughters the first animal and a doubt arises as to whether it might be a neveila, the second animal may not be slaughtered, though if one does so, he is not liable to the penalty of lashes.

Hilchos Shechita 12:6

Slaughter that can’t be eaten is still slaughter. Therefore, if one person slaughters a secular animal in the Temple courtyard, or a treifa, an ox condemned to stoning, a calf whose neck is to be broken, a red heifer or to an idol, it’s still slaughter even though these may not be eaten, so one who slaughters the second animal is liable to lashes. Similarly, if a person slaughtered the first animal and someone else slaughtered the second as a secular animal in the Temple courtyard, a condemned ox, a calf whose neck is to be broken or a red heifer, the latter is liable to the penalty of lashes. (Regarding slaughtering to an idol, see the next halacha.)