INDIANAPOLIS -- A man was fatally shot apparently as he was trying to buy drugs from someone on the city's northwest side Tuesday morning, police said.

Officers found Curtis Pratt, 49, of St. Louis, Mo., dead in a van after the mother of a woman who had been accompanying him called 911, police said.

Pratt had taken the woman, Matonya Johnson, 39, of Indianapolis, to the 1100 block of Eugene Street to buy a rock of cocaine early Tuesday, according to Johnson's mother, who didn't wish to be identified.

Pratt was shot during the apparent drug deal, and Johnson drove him away, police said.

"She was devastated and in shock because the guy shot him right in front of her," Johnson's mother said.

Johnson took Pratt to the Woodridge apartments, in the 2100 block of Shelburne Drive, near 71st Street and Michigan Road, at about 4:50 a.m., police said. Johnson's mother lives in the apartment complex and called 911.

Johnson's mother told 6News' Julie Pursley that a man with the street name "Little Darryl" was the shooter.

Police said they found several shell casings at the site of the shooting.

"We have to take it one step at a time -- determine where the crime happened, and what exactly happened. There's been some conflicting statements given," Indianapolis police Sgt. Paul Thompson said.

According to police, Johnson was being sought on an outstanding warrant in a drug case.

Her mother said the shooting was needless.

"You had to shoot him like he was an animal?" the woman said. "What kind of a person are you to do … a human being like that, regardless of what they were doing? You didn't have to take his life."

Police released no information about any possible suspects.