Does accessKeyId always appear in AssumeRole CloudTrail and in when the userIdentity is with temporary credentials

Hi, It's not clear from the documentation - does accessKeyId always appear in CloudTrail of AssumeRole events? Also, if the entity that assumed that former role does any action, will the accessKeyId in the userIdentity of the CloudTrail for that event be the same? Are there any occurrences that for the above events the accessKeyId does not appear in the CloudTrail?