CRANBERRY TWP — A suspected drug trafficker is jailed after getting caught up in an undercover investigation.

The Butler County Drug Task Force arrested Robert Lamar Jones, 38, of Pittsburgh on Friday after he allegedly sold crack cocaine to an undercover officer at a township home.

It was the fourth sale in less than three weeks involving Jones and the officer, authorities said.

The series of drug buys began Feb. 13 when a police informant set up a deal between 54-year-old William R. Reid and the officer at Reid’s home on Sherwood Drive, according to court documents.

Reid allegedly sold an eighth of an ounce of cocaine to the officer for $180. During the deal, investigators said, Reid identified himself as Jones’ source.

He also disclosed that he “kept a small amount of cocaine for himself as payment,” documents said.

Following the deal outside the home, surveillance officers nearby spotted Jones leaving the house in a car that was parked in the driveway.

The next day a similar deal was arranged, this time with Reid giving the officer a plastic bag containing suspected crack cocaine in exchange for $250.

While making the buy in the house, authorities said, the officer saw Jones seated at the kitchen table with bags of suspected drugs on it.

“Jones was using a scale to appear to sort, weigh and package the suspected narcotics,” documents said.

A third deal occurred Feb. 27 at the house where Reid and Jones allegedly sold one-quarter ounce of crack for $400.

The last deal unfolded about 6:15 p.m. Friday when the officer paid Jones another $400 for more crack, documents said.

Task force officers a short time later arrested Jones when he left the house. Investigators said he was found with the $400 in marked currency the undercover officer had given him.

Officers also seized the defendant’s cell phone and a small bag of suspected marijuana.

District Judge Lewis Stoughton arraigned Jones on four counts each of possession with intent to deliver a controlled substance, conspiracy, criminal use of a communication facility and possession of a controlled substance.

He is in the Butler County Prison on $50,000 bail.

County Detective Tim Fennell, who heads the drug task force, on Monday said that Reid is to turn himself in this week to be arraigned on unspecified charges.