BRENTWOOD - A high school sophomore from Central Islip has pleaded not guilty today to stabbing a man to death earlier this week.

Police say Mario Cruz, 17, killed 24-year-old Omar DeJesus Perez Sanchez, an immigrant from Guatemala who had only been in the U.S. for three months.

Sanchez's landlord, Francisco Cruz, says the 24-year-old man was the suspect's uncle, and the two spent time together Wednesday afternoon, which was the last time he saw his tenant alive.

Prosecutors say Cruz and Sanchez had a disagreement in a wooded area in Brentwood, and Cruz stabbed Sanchez in the chest. When the 24-year-old fell, the teen allegedly stabbed him again in the back and left him for dead.

The next morning, police say someone discovered Sanchez's body and called 911.

Cruz is being held without bail. He is due back in court next week.