A 47-year-old man is accused of stabbing another in the chest in Portland’s Old Town neighborhood in an unprovoked attack Tuesday night.

Ahmad Jamell Sloan Jr. was arraigned Thursday afternoon on an allegation of second-degree assault.

Sloan came out of nowhere, stabbed a man who was seated on the ground and leaning against a building at Northwest Glisan Street and Northwest Third Avenue about 9 p.m. on Tuesday, according to a probable cause affidavit.

Sloan stabbed Zach Stone once in the chest and then ran off, the affidavit says. Stone was able to alert someone in the building who called 911. An ambulance took Stone to OHSU Hospital, where he underwent surgery, according to police.

Video surveillance reviewed by police showed Sloan walk by Stone initially and then go around the building, before running back and stabbing Stone once, according to the affidavit. Sloan then ran west on Northwest Glisan.

“There is no interaction between the two men at any point, and Mr. Stone never moves from his seated position, nor looks up prior to the attack,’’ Multnomah County deputy district attorney Nicole M. Hermann wrote in the affidavit.

Early Wednesday morning, police located Sloan in the vicinity of the attack, wearing the same clothing as he wore when the assault occurred, according to police and prosecutors.

Upon arrest, the affidavit says, Sloan initially denied any involvement in the stabbing but also uttered, “I am sick of these punk (expletive), all they want is food and a place to sleep!’’

Sloan, who has reported to court authorities that he’s homeless and unemployed, has a lengthy record, including five felony convictions, 15 misdemeanor convictions and nine probation violations in Oregon, Washington and Iowa, according to court records. He has prior drug possession, robbery, assault and criminal mischief convictions in Multnomah County.

On June 25, he pleaded guilty in Multnomah County court to fourth-degree assault in connection with an unrelated incident on May 8. He was sentenced to 18 months probation.

At the time of the Old Town attack, he was on what the county calls “reduced supervision,’’ according to court records. He was ordered as part of his sentence to complete mental health treatment.

Sloan now is being held on $250,000 bail at the Multnomah County Detention Center. He’s due back in court next Friday.

-- Maxine Bernstein

Email at mbernstein@oregonian.com

Follow on Twitter @maxoregonian

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