According to a criminal complaint obtained by KDKA-TV, Keith Graves Jr. was arrested after allegedly robbing the Century Heritage Federal Credit Union at the Olympia Shopping Center in McKeesport earlier this month.

Around 1:30 p.m. on May 8, Allegheny County Police Department assisted the Versailles Borough Police Department in responding to a reported robbery at the credit union.

Investigators said a man first entered the bank claiming he wanted to open an account for himself and his son, but he did not have proper identification.

Police said the man returned a short time later and handed a teller a folded note demanding $50,000. According to the complaint, he then pulled out a rifle and said, “I ain’t [expletive] joking.”

The teller and another employee emptied cash from two drawers, totaling just under $2,300, authorities said.

Surveillance cameras at the shopping plaza allegedly showed Graves leaving the scene on a self-propelled scooter.

Detectives later discovered the robbery note had been left behind. Investigators determined it had been written on an elementary school spelling worksheet labeled “CKLA Spelling Practice, Unit 7, Week 1.”

After contacting administrators with the McKeesport Area School District, detectives learned the worksheet was used by third-grade students at Francis McClure Elementary School.

Meanwhile, one responding officer recognized the suspect from surveillance footage as the complainant in a domestic violence call earlier this year on Walnut Street.

Investigators then reviewed the school’s third-grade roster and found a student with the same last name who lived on Walnut Street. Police said the address matched records for Keith Graves. Authorities later saw Graves leaving the home Tuesday and took him into custody.

Graves faces multiple charges, including aggravated assault, robbery, recklessly endangering another person, simple assault, terroristic threats, and theft by unlawful taking.