Is a contract linguist a good job option for someone who plans to obtain a degree in criminal justice,who likes to travel,learn different languages and work with computers?

Wow! That career sounds pretty exciting to me. Because I’m not as familiar with this career as I’d like to be before I advise, please make sure you ask those in the field or closer to it. I read several articles, mostly from the link below, so I recommend you read the attachment along with my answer so you see where I put personal recommendations versus what the attachment says.

What struck me the most about your question versus the attachment was that your primary interest seems to be in criminal justice whereas the attachment is written for someone whose primary interest is in linguistics. If your primary life goal is in criminal justice, and you are not already bilingual, then my recommendation is not to pick linguistics.

The attachment says that the path to success as a linguist is to be considered a world-class expert in two or more languages. That requires a PhD in some aspect of linguistics and fluency in two or more languages. This would be a person called by the FBI as an expert witness (and hopefully a better expert than the defendant has) to testify in court that the two recordings in evidence, even though one is distorted, were both made by the same person.

In order to be successful in criminal justice, your educational credentials should show knowledge and commitment in that field. Your plan for a Bachelor’s and Masters in that field does just that. You catch the bad guys and call a contract linguist to testify that your guy is the one who did it, and for the next case you call a handwriting expert.

But this does not mean that your interest in languages and travel and even computers needs to be abandoned. On the contrary, you should study abroad, take language classes for the general credit requirements in your criminal justice degrees, even ask for foreign assignments after Quantico. You can still be very knowledgeable and be known within the FBI as an “specialist” in linguistics, maybe even an “expert”, but outside the FBI you would be a Fed who knows a couple of languages.

https://study.com/articles/Become_a_Linguist_Step-by-Step_Career_Guide.html