Musannaf Ibn Abi Shaybah 38596 — the first to do a thing, and who did

Al-Walid bin Jumay' said: My grandmother narrated to me that a slave of Sayyidah Umm Waraqah bint Abdullah bin al-Harith al-Ansari (may Allah be pleased with her) and a slave-girl of hers together smothered and killed her during the rule of Sayyiduna Umar (may Allah be pleased with him), and they ran away. They were then caught and brought to Sayyiduna Umar (may Allah be pleased with him), and he had them both crucified. They were the first two people to be crucified in Madinah.