Tyrese Devon Haspil, 21, is expected to face second-degree murder and other charges after Saleh's sister discovered the gruesome scene that included large plastic bags and an electric saw still plugged into the wall.
The motive, sources said, appeared to be a business dispute and the theft of tens of thousands of dollars.
The 33-year-old tech entrepreneur was found decapitated and dismembered on Tuesday. Authorities later revealed that Saleh was stabbed to death.
Saleh used a key fob to select his floor in the elevator Monday, but surveillance video shows a man wearing black and carrying a bag following him on and acting like he selected a different floor.
But when they arrived on the seventh floor, the man followed Saleh off, and possibly knocked him out with a taser.
Police say the murderer used a power saw to dismember the body -- an act that was possibly interrupted when Saleh's sister called up from the street, causing the suspect to flee down the fire stairs.
Friends previously described Saleh as a brash and innovative entrepreneur who started businesses in Nigeria and elsewhere in the developing world.
Detectives recovered text messages between Saleh and Haspil in which Saleh accused the suspect of stealing the money.
Sources say the suspect was tracked by his credit card, believed paid for by Saleh, which paid for the electric saw used after the murder.
Gokada released the following statement about their CEO:
"A leader, innovator and inspiration, Fahim's passion for Nigeria and its youth was immeasurable. He believed that technology could transform lives and improve safety and efficiency. He built Gokada to act upon these beliefs.
Under Fahim's leadership, Gokada has grown to become Nigeria's leading fully integrated delivery and logistics company, with outstanding growth and profitability metrics. Gokada has been built with a strong and resilient workforce that has navigated and transitioned through challenges, while keeping to its core values.
Gokada is committed to the well being of all of its employees, and believe it is important to take this time to support members of the team, as they pull through a devastating loss."