Someone can correct me?

because he was not directly responsible for the death of his friend, Lakeith Smith rejected the arrangement proposed by the prosecutor. his friends having accepted, they were sentenced to 30 years in prison, where Lakeith Smith will have 65 to serve.
He will have had a longer punishment than he will have, because he rebelled against an unfair system. in spite of the fact that he had a part in the crimes committed that evening, he is undoubtedly the one who was the least guilty among all. He was young, he followed his group of friends, he was not armed, he was black.

Thank you 😁

Because he was not directly responsible for the death of his friend, Lakeith Smith rejected the arrangement proposed by the prosecutor. His friends, having accepted, were sentenced to 30 years in prison whereas Lakeith Smith received 65 years. He was given a longer punishment than he would have had because he rebelled against an unfair system. In spite of the fact that he had a part in the crimes committed that evening, Lakeith is undoubtedly the least guilty among them all. He is a young black individual who, unarmed, followed his group of friends.

Good passage! Just a few tense fixes and some sentence reorganization. But the meaning of each sentence was clear and straightforward.