Short answer. Yes. A prior conviction of a crime is not, by itself, a ground for disqualifying someone as a witness, unless a specific law provides otherwise. Anyone who can perceive events and communicate that perception to others may generally testify, regardless of their criminal record.
What the law says
All persons who can perceive, and perceiving, can make known their perception to others, may be witnesses. Religious or political belief, interest in the outcome of the case, or conviction of a crime, unless otherwise provided by law, shall not be a ground for disqualification.
Rule 130, Section 21 — Witnesses; their qualifications. Read the full provision →
The general test is perception and the ability to communicate it
The rule sets a broad baseline: all persons who can perceive, and perceiving, can make known their perception to others, may be witnesses. Competence to testify does not turn on someone's background, reputation, or personal history — it turns on whether they can actually perceive relevant events and then communicate what they perceived to the court in a way that others present can readily understand and evaluate.
A conviction of a crime is expressly not a disqualifying ground
The same provision states directly that conviction of a crime, unless otherwise provided by law, shall not be a ground for disqualification. A witness with a criminal record is not barred from testifying simply because of that record; the rule places this on the same footing as religious belief, political belief, and having an interest in the case outcome — none of which disqualifies a witness by itself either, absent some other specific statutory bar.
The exception for other laws is narrow, not a general escape hatch
The phrase unless otherwise provided by law means some other specific statute, not this rule itself, would have to create a disqualification tied to a particular kind of conviction or a particular kind of proceeding. Absent such a specific law, a criminal conviction on its own — regardless of how serious the underlying offense was — does not by itself keep someone off the witness stand.
The record can still affect how much weight testimony gets
Not being disqualified is different from being immune from scrutiny. A witness's criminal record, like other circumstances bearing on their credibility, can still be raised and weighed by the court when it decides how much to believe that witness — the rule addresses whether someone may testify at all, not how convincing their testimony ultimately turns out to be once it is actually given in open court.
Why this distinction matters for parties assessing a witness
A party should not assume a potential witness is unusable simply because that witness has a criminal conviction in their past. Unless a specific law provides otherwise for that particular kind of case, such a witness remains competent to testify, and any concern about their record is properly addressed through cross-examination and argument about credibility, not through outright exclusion of their testimony from the proceedings entirely at the outset.