If a patient gives an evident clear sign by nodding

Narrated Anas:

A Jew crushed the head of a girl between two stones. She was asked, "Who has done so to you, so-and-so? So-and-so?" Till the name of the Jew was mentioned, whereupon she nodded (in agreement). So the Jew was brought and was questioned till he confessed. The Prophet then ordered that his head be crushed with stones.

حَدَّثَنَا حَسَّانُ بْنُ أَبِي عَبَّادٍ، حَدَّثَنَا هَمَّامٌ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ ـ رضى الله عنه ـ أَنَّ يَهُوِدِيًّا، رَضَّ رَأْسَ جَارِيَةٍ بَيْنَ حَجَرَيْنِ، فَقِيلَ لَهَا مَنْ فَعَلَ بِكِ، أَفُلاَنٌ أَوْ فُلاَنٌ حَتَّى سُمِّيَ الْيَهُودِيُّ، فَأَوْمَأَتْ بِرَأْسِهَا، فَجِيءَ بِهِ، فَلَمْ يَزَلْ حَتَّى اعْتَرَفَ، فَأَمَرَ النَّبِيُّ ﷺ فَرُضَّ رَأْسُهُ بِالْحِجَارَةِ.