Sa'id bin Jubayr (may Allah have mercy on him) said: Whoever commits highway robbery is the one who wages war. He also said: If he has only killed, he is to be killed; if he has taken property along with killing, he is to be killed and then crucified; if he has only taken property and not killed, his hand and foot are to be cut off. If he repents, that is between him and Allah, and the hadd will (still) be established.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السرقة / 17319